chore: Double shard count and drop ubuntu-lastest from the nightly …

…build (#5518)

Should make make the nightly build more predictable

.github/workflows/integration-tests-reusable.yml

@@ -27,15 +27,15 @@ jobs:
  - name: Populate OS list (all platforms)
  id: populate-os-list-all
  if: inputs.all_platforms
- run: echo "os-list=[\"ubuntu-latest\", \"ubuntu-20.04\", \"macos-latest\", \"windows-2019\"]" >> $GITHUB_OUTPUT
+ run: echo "os-list=[\"ubuntu-20.04\", \"macos-latest\", \"windows-2019\"]" >> $GITHUB_OUTPUT
  - name: Populate OS list (one platform)
  id: populate-os-list-one
  if: "!inputs.all_platforms"
  run: echo "os-list=[\"ubuntu-20.04\"]" >> $GITHUB_OUTPUT
  - name: Populate OS mapping for package.py
  id: populate-os-mapping
  run: |
- echo "os-mapping={\"ubuntu-latest\": \"ubuntu\", \"ubuntu-20.04\": \"ubuntu\", \"macos-latest\": \"macos\", \"windows-2019\": \"windows\"}" >> $GITHUB_OUTPUT
+ echo "os-mapping={\"ubuntu-20.04\": \"ubuntu\", \"macos-latest\": \"macos\", \"windows-2019\": \"windows\"}" >> $GITHUB_OUTPUT
  - name: Populate target runtime version list (all platforms)
  id: populate-target-runtime-version-all
  if: inputs.all_platforms

.github/workflows/nightly-build-reusable.yml

@@ -25,7 +25,7 @@ jobs:
  with:
  ref: ${{ inputs.ref }}
  all_platforms: true
- num_shards: 5
+ num_shards: 10
 
  determine-vars:
  if: github.repository_owner == 'dafny-lang' && inputs.publish-prerelease