chore(python): Enable additional ruff lint rule sets

[alexander-beedie]

Was adding a lot of additional linting at work, and saw some value in enabling a few additional ruff rule sets here too.

Additional rule sets

"ANN",  # flake8-annotations
"ICN",  # flake8-import-conventions
"INT",  # flake8-gettext
"PERF", # perflint
"PYI",  # flake8-pyi

• Various minor nitpicks/consistency (eg: we sometimes did and sometimes didn't annotate the return from __init__ methods with -> None, and now we do so consistently everywhere), and so on. Nothing that looks especially controversial ;)

• Some decent catches too, such as properly typing the return from context manager __enter__ with -> Self, and a few unnecessary list/dict comprehensions were spotted and suggested for optimisation.

Also

• Minor version bump for ruff (from "0.6.3" to "0.6.4").

[codecov]

Codecov Report

Attention: Patch coverage is 94.82759% with 3 lines in your changes missing coverage. Please review.

Project coverage is 79.88%. Comparing base (0e5e554) to head (616a9c2).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
py-polars/polars/dataframe/frame.py	80.00%	1 Missing ⚠️
py-polars/polars/io/delta.py	0.00%	1 Missing ⚠️
py-polars/polars/lazyframe/frame.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #18721      +/-   ##
==========================================
- Coverage   79.90%   79.88%   -0.02%     
==========================================
  Files        1513     1513              
  Lines      203465   203467       +2     
  Branches     2892     2892              
==========================================
- Hits       162579   162547      -32     
- Misses      40338    40372      +34     
  Partials      548      548              

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