🧪 Pin latest to macos-13 @ CI

[webknjaz]

macos-latest now corresponds to macos-14-arm64 which is not yet compatible with the lock files we got.

❓ What kind of change does this PR introduce?

• 🐞 bug fix
• 🐣 feature
• 📋 docs update
• 📋 tests/coverage improvement
• 📋 refactoring
• 💥 other

📋 What is the related issue number (starting with #)

N/A

❓ What is the current behavior? (You can also link to an open issue here)

The macos-latest jobs fail in CI.

❓ What is the new behavior (if this is a feature change)?

They shouldn't.

📋 Other information:

macos-latest switched to macos-14-arm64 suddenly (it was macos-12 a day ago).

Refs:

• Cargo lo longer available on macOS-latest actions/runner-images#9732
• macOS ARM (macos-14) has rendering issues with lines and texture when using OpenGL actions/runner-images#9712

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• I wrote descriptive pull request text above
• I think the code is well written
• I wrote good commit messages
• I have squashed related commits together after
  the changes have been approved
• Unit tests for the changes exist
• Integration tests for the changes exist (if applicable)
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This change is