Since we already finished v26.1 upgrade in https://github.com/grpc/grpc/pull/35796
<!--
If you know who should review your pull request, please assign it to that
person, otherwise the pull request would get assigned randomly.
If your pull request is for a specific language, please add the appropriate
lang label.
-->
Closes#36230
PiperOrigin-RevId: 623960260
### NOTE
* We shouldn't merge this PR until GCP cloud functions drops support for Python 3.7 ([Currently scheduled for GCF](https://cloud.google.com/functions/docs/runtime-support#python))
As part of supporting Python 3.12, we're now officially drop support for Python 3.7.
This PR:
* Changed supported Python version from 3.7 to 3.8 in README.
* Replaced distribution test image from `debian:buster` to `debian:bullseye` since the default Python version in buster is 3.7.
<!--
If you know who should review your pull request, please assign it to that
person, otherwise the pull request would get assigned randomly.
If your pull request is for a specific language, please add the appropriate
lang label.
-->
Closes#34450
PiperOrigin-RevId: 622899511
Support Python 3.12.
### Testing
* Passed all Distribution Tests.
* Also tested locally by installing 3.12 artifact.
<!--
If you know who should review your pull request, please assign it to
that
person, otherwise the pull request would get assigned randomly.
If your pull request is for a specific language, please add the
appropriate
lang label.
-->
- Switched from yapf to black
- Reconfigure isort for black
- Resolve black/pylint idiosyncrasies
Note: I used `--experimental-string-processing` because black was
producing "implicit string concatenation", similar to what described
here: https://github.com/psf/black/issues/1837. While currently this
feature is experimental, it will be enabled by default:
https://github.com/psf/black/issues/2188. After running black with the
new string processing so that the generated code merges these `"hello" "
world"` strings concatenations, then I removed
`--experimental-string-processing` for stability, and regenerated the
code again.
To the reviewer: don't even try to open "Files Changed" tab 😄 It's
better to review commit-by-commit, and ignore `run black and isort`.
* Support Python 3.11
* Update build images for 3.11
* Whoopsie
* The architecture of this thing is garbage
* Silence ownership warning
* Account for change in git behavior
* Fix directory
* I am in great pain
* Update Windows and arm linux
* Agh
* Clean up
* Add Python 3.10.0rc1 binary wheels
* Drop Python 3.5 artifacts
* Document the drop of 3.5
* Fix the wrong pip pointer
* Update manylinux2014 to a newer version, remove 3.5 distribtest
* Update manylinux aarch64 to see if the absl error go away
* Use the preferred alias
* Allow different wheel library to produce different tag order
* Remove unused shell var and log produced wheels
* Use copy instead of move
* Make bash happy about the wildcard
* Upgrade the debian image to use 3.5+ Python
* Polish the comments for the Dockerfiles
* Add isort_code.sh to sanity tests
* Run tools/distrib/isort_code.sh
* Fine tune the import order for relative imports
* Make pylint and project generation happy
* Fix a few corner cases
* Use --check instead of --diff
* The import order impacts test result somehow
* Make isort print diff and check output at the same time
* Let tools/run_tests/python_utils be firstparty library
* Run isort against latest HEAD
* Remove Python 2.7 binary wheels
* Make sure pip won't pick-up newer versions
* Attempt to fix the distribtest
* Fallback to virtualenv==16.7.9 for 34 and 35
* Remove 34 from binary wheel distribtests