chore: Use 3.11 for integration tests

[rzhao271]

This PR changes the CI to use Python 3.11 instead of 3.10, and attempts to fix a small deprecation warning.

It also adds a new lint ignore rule for ruff because CI gave the following errors:

Run ruff --format=github .
Error: pylib/gyp/generator/ninja.py:2095:24: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcode_emulation.py:153:23: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcode_emulation.py:154:28: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcode_emulation.py:155:23: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcode_emulation.py:159:20: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcode_emulation.py:163:30: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:268:15: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:272:26: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:285:36: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:1685:16: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:2071:36: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:2080:37: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: pylib/gyp/xcodeproj_file.py:2460:26: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
Error: Process completed with exit code 1.

[cclauss]

@dhruvmanila Can you please propose solutions to ruff rule RUF012 in a separate pull request when you get a chance?