Use Windows arm64 hosted runners for build-windows-msi

Author: hugovk

.github/workflows/build.yml

@@ -179,18 +179,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os:
-        - windows-latest
         arch:
         - x86
         - x64
-        include:
-          # 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
+        - arm64
     uses: ./.github/workflows/reusable-windows-msi.yml
     with:
-      os: ${{ matrix.os }}
       arch: ${{ matrix.arch }}
 
   build-macos:

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

@@ -3,10 +3,6 @@ name: Reusable Windows MSI
 on:
   workflow_call:
     inputs:
-      os:
-        description: OS to run on
-        required: true
-        type: string
       arch:
         description: CPU architecture
         required: true
@@ -21,7 +17,7 @@ env:
 jobs:
   build:
     name: installer for ${{ inputs.arch }}
-    runs-on: ${{ inputs.os }}
+    runs-on: ${{ inputs.arch == 'arm64' && 'windows-11-arm' || 'windows-latest' }}
     timeout-minutes: 60
     env:
       ARCH: ${{ inputs.arch }}
@@ -31,7 +27,5 @@ jobs:
       with:
         persist-credentials: false
     - name: Build CPython installer
-      # Forks don't have access to Windows on Arm runners. Skip those:
-      if: inputs.arch != 'arm64' || github.repository_owner == 'python'
       run: ./Tools/msi/build.bat --doc -"${ARCH}"
       shell: bash