Restrict WoA for forks

Author: diegorusso

.github/workflows/build.yml

@@ -163,13 +163,17 @@ jobs:
         free-threading:
           - false
           - true
+        is-fork:  # only used for the exclusion trick
+        - ${{ github.repository_owner != 'python' }}
         include:
           - os: windows-aarch64
             arch: arm64
             free-threading: false
+            is-fork: false
           - os: windows-aarch64
             arch: arm64
             free-threading: true
+            is-fork: false
           - os: windows-latest
             arch: Win32
             free-threading: false
@@ -192,9 +196,12 @@ jobs:
         arch:
           - x86
           - x64
+        is-fork:  # only used for the exclusion trick
+        - ${{ github.repository_owner != 'python' }}
         include:
           - os: windows-aarch64
             arch: arm64
+            is-fork: false
     uses: ./.github/workflows/reusable-windows-msi.yml
     with:
       os: ${{ matrix.os }}

.github/workflows/jit.yml

@@ -74,7 +74,8 @@ jobs:
             runner: windows-latest
           - target: aarch64-pc-windows-msvc/msvc
             architecture: ARM64
-            runner: windows-aarch64
+            # Forks don't have access to Windows on Arm runners. These jobs are skipped below:
+            runner: ${{ github.repository_owner == 'python' && 'windows-aarch64' || 'windows-latest' }}
           - target: x86_64-apple-darwin/clang
             architecture: x86_64
             runner: macos-13
@@ -96,7 +97,8 @@ jobs:
           python-version: '3.11'
 
       - name: Native Windows
-        if: runner.os == 'Windows'
+        # Forks don't have access to Windows on Arm runners. Skip those:
+        if: runner.os == 'Windows' && (matrix.architecture != 'ARM64' || github.repository_owner == 'python')
         run: |
           choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
           ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }}