Begin MacOS x86-64 wind down...

[jay0lee]

https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/

• The macos-13 x86-64 image we are using will start browning out in Nov and be turned off in Dec. We should just go ahead and remove it here in late Oct to avoid the drama. MacOS 13 is already at end of life.

• We are already building on macos-15-intel. This build will work on Intel Macs running 15 and 26. MacOS 14 users must upgrade to 15 or 26 to continue to use GAM on Intel Macs.

• Github has already stated that ``macos-15-intelwill be shutdown Fall 2027 and they have no plans to addmacos-26-intel` images. Thus there will be a one year gap where there are some Intel Macs that are still supported by Apple but we won't be able to build GAM on them. Personally I'm OK with this, the writing has been on the wall for Intel Macs for years already.

Note that the above only applies to GAM binaries. If Intel Mac users can install a supported version of Python 3.10+ as of now but generally jumping a minor version each year) then they can install GAM7 with pip:

pip install gam7