gh-120111: Don't use cirrus M1 macOS runners on fork (#120116)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

.github/workflows/build.yml

@@ -199,8 +199,9 @@ jobs:
     uses: ./.github/workflows/reusable-macos.yml
     with:
       config_hash: ${{ needs.check_source.outputs.config_hash }}
-      # Cirrus is M1, macos-13 is default GHA Intel
-      os-matrix: '["ghcr.io/cirruslabs/macos-runner:sonoma", "macos-13"]'
+      # Cirrus and macos-14 are M1, macos-13 is default GHA Intel.
+      # Cirrus used for upstream, macos-14 for forks.
+      os-matrix: '["ghcr.io/cirruslabs/macos-runner:sonoma", "macos-14", "macos-13"]'
 
   build_macos_free_threading:
     name: 'macOS (free-threading)'
@@ -210,8 +211,9 @@ jobs:
     with:
       config_hash: ${{ needs.check_source.outputs.config_hash }}
       free-threading: true
-      # Cirrus is M1
-      os-matrix: '["ghcr.io/cirruslabs/macos-runner:sonoma"]'
+      # Cirrus and macos-14 are M1.
+      # Cirrus used for upstream, macos-14 for forks.
+      os-matrix: '["ghcr.io/cirruslabs/macos-runner:sonoma", "macos-14"]'
 
   build_ubuntu:
     name: 'Ubuntu'

.github/workflows/reusable-macos.yml

@@ -14,7 +14,7 @@ on:
 
 jobs:
   build_macos:
-    name: 'build and test'
+    name: build and test (${{ matrix.os }})
     timeout-minutes: 60
     env:
       HOMEBREW_NO_ANALYTICS: 1
@@ -27,6 +27,13 @@ jobs:
       fail-fast: false
       matrix:
         os: ${{fromJson(inputs.os-matrix)}}
+        is-fork:
+          - ${{ github.repository_owner != 'python' }}
+        exclude:
+          - os: "ghcr.io/cirruslabs/macos-runner:sonoma"
+            is-fork: true
+          - os: "macos-14"
+            is-fork: false
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4