Fix macOS CI builds

[lurch]

By removing cmake and pkg-config from the dependencies

Apparently they're already included: https://github.com/actions/runner-images/blob/macos-14-arm64/20241119.505/images/macos/macos-14-arm64-Readme.md

And they were causing warnings / errors in the GitHub CI macOS builds:

Warning: Treating cmake as a formula. For the cask, use homebrew/cask/cmake or specify the `--cask` flag. To silence this message, use the `--formula` flag.
Warning: cmake 3.31.0 is already installed and up-to-date.
To reinstall 3.31.0, run:
  brew reinstall cmake

==> Pouring pkgconf--2.3.0_1.arm64_sonoma.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /opt/homebrew
Could not symlink bin/pkg-config
Target /opt/homebrew/bin/pkg-config
is a symlink belonging to pkg-config@0.29.2. You can unlink it:
  brew unlink pkg-config@0.29.2

To force the link and overwrite all conflicting files:
  brew link --overwrite pkgconf

To list all files that would be deleted:
  brew link --overwrite pkgconf --dry-run

Possible conflicting files are:
/opt/homebrew/bin/pkg-config -> /opt/homebrew/Cellar/pkg-config@0.[29](https://github.com/FrameworkComputer/picotool/actions/runs/11924333330/job/33234474972#step:5:30).2/0.29.2_3/bin/pkg-config
/opt/homebrew/share/aclocal/pkg.m4 -> /opt/homebrew/Cellar/pkg-config@0.29.2/0.29.2_3/share/aclocal/pkg.m4
/opt/homebrew/share/man/man1/pkg-config.1 -> /opt/homebrew/Cellar/pkg-config@0.29.2/0.29.2_3/share/man/man1/pkg-config.1

(see also raspberrypi/pico-sdk#2050 - I guess GitHub must have been doing a bunch of updates to their CI infrastructure recently!)

[will-v-pi]

Do you know why they are only causing errors for some of the CI builds but not others?

[lurch]

Do you know why they are only causing errors for some of the CI builds but not others?

Perhaps different GitHub CI runners are running slightly different versions of their CI OS images? 🤷 (So if you were lucky you would get an old CI OS which still worked, but if you were "unlucky" you'd get the latest CI OS images which caused errors?)

EDIT: Yeah, I just randomly picked one of the Mac CI jobs on this PR, and that was still using https://github.com/actions/runner-images/blob/macos-14-arm64/20241022.361/images/macos/macos-14-arm64-Readme.md whereas the errors I posted in my original comment were coming from the 20241119.505 version.

[kilograham]

github seem also to have decided to only fail builds on some days (i kid not) ;-)

[lurch]

Any day that has an 'a' in it's name? 😆

[ndabas]

Apparently Windows has had similar issues too.