[Workflow] Add way to opt in or out of build platforms

[amoeba]

Driver developers may not have their driver working on the same set of platforms we use in CI, which is currently,

      matrix:
        include:
          - { platform: linux, arch: amd64, runner: ubuntu-latest }
          - { platform: macos, arch: arm64, runner: macos-latest }
          - { platform: win, arch: amd64, runner: windows-latest }

For example, a driver developer may choose to skip Windows as a target and they may do this because of a blocking issue they can't resolve.

How this works is somewhat important because we want it to be the default state that drivers get built for the largest set of platforms possible. Therefore I think a mechanism to opt out of a platform is probably better than one to opt into each platform.

[lidavidm]

(We actually build on linux-arm64 too, we just don't run tests on it)