Replace remaining utcnow calls + add ruff check

[cdce8p]

Proposed change

Fix Python 3.12 deprecations, followup to #93684

• Replace datetime.utcnow()
• Add ruff checks: DTZ003 and DTZ004
  https://beta.ruff.rs/docs/rules/#flake8-datetimez-dtz

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
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