[exporter/datadogexporter] Add support for custom container tags (ope…

…n-telemetry#29156)

**Description:**
This PR updates `github.com/DataDog/datadog-agent/pkg/trace` and
`github.com/DataDog/opentelemetry-mapping-go/pkg/otlp/attributes`. This
brings in the following PRs:
DataDog/opentelemetry-mapping-go#193,
DataDog/datadog-agent#20779 which add support
for custom container tags (for traces, metrics and logs) via resource
attributes prefixed by `datadog.container.tag.*`.

This PR also brings a couple other changes for traces which are
reflected in the changelog:
- Stop extracting container tags from span attributes, but only extract
from resource attributes. The semantic conventions we are using to
extract the container tags are meant for resource attributes, so we
should only check resource attributes.
- Stop setting the DD Format container tags as span tags, but only set
these in the dedicated container tag (`_dd.container.tag`). We currently
set the DD mapped container tags both as span tag, and in the dedicated
container tag `_dd.tags.container`. This should only be set in the
dedicated container tag.

The update to opentelemetry-mapping-go also brings in this change:
DataDog/opentelemetry-mapping-go#174, which adds
support for `host.cpu.*` attributes.

.chloggen/mackjmr_fix-container-tags-resource-attributes.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: datadogexporter
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Only extract DD container tags from resource attributes. Previously, container tags were also extracted from span attributes.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29156]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

.chloggen/mackjmr_fix-container-tags-span-tags.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: datadogexporter
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Only add container tags in dedicated container tag section. Previously, container tags were also added as span tags. Container tags will now only be accessible via the span container tab, and not as span tags.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29156]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

.chloggen/mackjmr_host-cpu-attributes.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: datadogexporter
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add support for host.cpu attributes.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29156]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

.chloggen/mackjmr_update-mapping-go-and-package-trace.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: datadogexporter
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add support for custom container tags via resource attributes prefixed by `datadog.container.tag.*`.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29156]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []