Implement Python CSM observability.
Design: [go/grpc-python-opentelemetry](http://goto.google.com/grpc-python-opentelemetry)
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Closes#36557
PiperOrigin-RevId: 639073741
Actually build O11y artifacts.
### Testing
* Manually installed the `.whl` and verified it's working locally (For Python 3.8 + Linux).
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Closes#35578
PiperOrigin-RevId: 600566829
- 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`.
* Use latest pylint in Python 3.7 (they dropped support for PY2)
* Make latest pylint happy
* Forced to upgrade to shellcheck 0.4.4
* Make shellcheck 0.4.4 happy
* Adopt reviewers' advice to reduce global disabled rules