chore: bump to macos-13

[pfeerick]

GitHub is ending macos-12 support in December 2024, and is already throttling the build duration for this target as of July.

The macOS 12 runner image will be removed by December 3rd, 2024. To raise awareness of the upcoming removal, jobs using macOS 12 will temporarily fail during scheduled time periods defined below:

November 4, 9:00 AM - 7:00 PM EST November 11, 9:00 AM - 7:00 PM EST November 18, 9:00 AM - 7:00 PM EST November 25, 9:00 AM - 7:00 PM EST

ref: https://github.com/actions/runner-images/issues/10721