refactor!: rename all remaining metadata to meta

[anakin87]

Related Issues

• part of Change metadata to meta #6570
• continues the work done in changed metadata to meta #6605 and chore: replace metadata w meta in tests/examples #6612

Proposed Changes:

• change metadata to meta
• (in some cases, I may gone a little too far with the renaming, but probably it's not a problem)

How did you test it?

CI

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[julian-risch]

LGTM! 👍 Better make changes like this as soon as possible rather than later. Our new tutorials don't use meta so they are not affected. Advent challenges I haven't checked. I could well imagine that there are some docs pages with code snippets that need to be updated. Could you please sync with @dfokina on this? Thank you!

[anakin87]

Thanks, @julian-risch.

I'm syncing with Daria and Devrel. Luckily, Advent challenges are not affected.