Install missing winget on the windows-11-arm runner

Author: EliahKagan

.github/workflows/ci.yml

@@ -234,6 +234,9 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
+      - name: Set up WinGet
+        if: matrix.os == 'windows-11-arm'
+        run: Add-AppxPackage -RegisterByFamilyName -MainPackage Microsoft.DesktopAppInstaller_8wekyb3d8bbwe
       - name: Upgrade Git for Windows
         if: startsWith(matrix.os, 'windows')
         run: winget upgrade git --accept-source-agreements
@@ -288,6 +291,9 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
+      - name: Set up WinGet
+        if: matrix.os == 'windows-11-arm'
+        run: Add-AppxPackage -RegisterByFamilyName -MainPackage Microsoft.DesktopAppInstaller_8wekyb3d8bbwe
       - name: Upgrade Git for Windows
         run: winget upgrade git --accept-source-agreements
       - uses: actions/checkout@v6