x/build: have darwin/arm64 builders on macOS 13 (Ventura)

[dmitshur]

Apple announced macOS 13 Ventura during WWDC 2022 earlier in the year. Its preview page currently says "Coming this October", which is coming up. This is the tracking issue for a builder that provides coverage for it.

For arm64 specifically, I expect we can take out some of the existing macOS 11-12 builders from their pool and update them to test with 13.

CC @golang/release, @golang/darwin.

[heschi]

cc @prattmic

[dmitshur]

This was done a while back (CL 532579).