[CI] Update macOS workers to macos-latest

[Faless]

GitHub actions no longer allow macos-11 runners.

See https://github.com/godotengine/godot-cpp/actions/runs/9551620476

[dsnopek]

Thanks!

However, looking at Godot's CI, it's using macos-latest. Is there a reason we shouldn't do the same in godot-cpp?

[adamscott]

Is there a reason we shouldn't do the same in godot-cpp?

I don't think so, I suggest that this PR sets the builder to macos-latest.

[Faless]

However, looking at Godot's CI, it's using macos-latest. Is there a reason we shouldn't do the same in godot-cpp?

Updated to use macos-latest

[dsnopek]

Thanks!

[dsnopek]

Cherry-picked for 4.2 in PR #1527

[dsnopek]

Cherry-picked for 4.1 in PR #1529