python-blosc2 release procedure

Preliminaries

Do not worry about the version number. setuptools_scm in scikit-build-core has machinery to figure it out based on git tags: https://scikit-build-core.readthedocs.io/en/latest/configuration.html#dynamic-metadata
Make sure that the c-blosc2 repository is updated to the latest version (or a specific version that will be documented in the RELEASE_NOTES.md). In CMakeLists.txt edit:
```
FetchContent_Declare(blosc2
    GIT_REPOSITORY https://github.com/Blosc/c-blosc2
    GIT_TAG b179abf1132dfa5a263b2ebceb6ef7a3c2890c64
)
```
to point to the desired commit/tag in the c-blosc2 repo.
Make sure that the current main branch is passing the tests in continuous integration.
Build the package and make sure that:
```
python -c "import blosc2; blosc2.print_versions()"
```
is printing the correct versions.
Make sure that RELEASE_NOTES.md and ANNOUNCE.rst are up to date with the latest news in the release.

Commit the changes:

git commit -a -m "Getting ready for release X.Y.Z"
git push

Double check that the supported Python versions for the wheels are the correct ones (.github/workflows/cibuildwheels.yml). Add/remove Python version if needed. Also, update the classifiers field for the supported Python versions.
Check that the metainfo for the package is correct:
```
python -m build --sdist
twine check dist/*
```

Create a (signed, if possible) tag X.Y.Z from main. Use the next message:
```
git tag -a vX.Y.Z -m "Tagging python-blosc2 version X.Y.Z"
```
Push the tag to the github repo:
```
git push --tags
```
Make sure that the tag is passing the tests in continuous integration (this may take more than an hour).
Update the latest release in the doc/python-blosc2.rst file with the new version number (and date?). Do a commit:
```
git commit -a -m "Update latest release in doc"
git push
```
Go to Blosc/blogsite repo, then to "Actions", click on the most recent workflow run (at the top of the list), and then click on the "Re-run all jobs" button to regenerate the documentation and check that it has been correctly updated in https://www.blosc.org.

Check that the package (and wheels!) have been uploaded to PyPI (they should have been created when GHA would finish the tag trigger): https://pypi.org/project/blosc2/

Check that the packages and wheels are sane:

pip install blosc2[test] -U
python -c "import blosc2; blosc2.print_versions()"
pytest

Do an actual release in github by visiting: https://github.com/Blosc/python-blosc2/releases/new Add the notes specific for this release This will upload the wheels to PyPI too.

Send an announcement to the Blosc and PyData lists. Use the ANNOUNCE.rst file as skeleton (or possibly as the definitive version). Start the subject with ANN:.
Announce in Mastodon via https://fosstodon.org/@Blosc2 account and rejoice.

Change back to the actual python-blosc2 repo:
```
cd $HOME/blosc/python-blosc2
```
Create a new header for adding new features in RELEASE_NOTES.md with a placeholder text:
```
## Changes from X.Y.Z to X.Y.(Z+1)

XXX version-specific blurb XXX
```

Commit your changes with:

git commit -a -m "Post X.Y.Z release actions done"
git push

That's all folks!