Disable WoA runners on forks

Author: diegorusso

.github/workflows/build.yml

@@ -163,17 +163,15 @@ jobs:
         free-threading:
           - false
           - true
-        is-fork:  # only used for the exclusion trick
-        - ${{ github.repository_owner != 'python' }}
         include:
-          - os: windows-aarch64
+          # Forks don't have access to Windows on Arm runners. These jobs are skipped below:
+          - os: ${{ github.repository_owner == 'python' && 'windows-aarch64' || 'windows-latest' }}
             arch: arm64
             free-threading: false
-            is-fork: false
-          - os: windows-aarch64
+          # Forks don't have access to Windows on Arm runners. These jobs are skipped below:
+          - os: ${{ github.repository_owner == 'python' && 'windows-aarch64' || 'windows-latest' }}
             arch: arm64
             free-threading: true
-            is-fork: false
           - os: windows-latest
             arch: Win32
             free-threading: false
@@ -196,12 +194,10 @@ jobs:
         arch:
           - x86
           - x64
-        is-fork:  # only used for the exclusion trick
-        - ${{ github.repository_owner != 'python' }}
         include:
-          - os: windows-aarch64
+          # Forks don't have access to Windows on Arm runners. These jobs are skipped below:
+          - os: ${{ github.repository_owner == 'python' && 'windows-aarch64' || 'windows-latest' }}
             arch: arm64
-            is-fork: false
     uses: ./.github/workflows/reusable-windows-msi.yml
     with:
       os: ${{ matrix.os }}

.github/workflows/reusable-windows-msi.yml

@@ -20,6 +20,7 @@ env:
 
 jobs:
   build:
+    if: inputs.arch != 'ARM64' || github.repository_owner == 'python'
     name: installer for ${{ inputs.arch }}
     runs-on: ${{ inputs.os }}
     timeout-minutes: 60

.github/workflows/reusable-windows.yml

@@ -24,6 +24,8 @@ env:
 
 jobs:
   build:
+    # Forks don't have access to Windows on Arm runners. Skip those:
+    if: inputs.arch != 'ARM64' || github.repository_owner == 'python'
     name: Build and test (${{ inputs.arch }})
     runs-on: ${{ inputs.os }}
     timeout-minutes: 60