Install missing winget on the windows-11-arm runner

Author: EliahKagan

.github/workflows/ci.yml

@@ -254,6 +254,9 @@ 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
@@ -326,6 +329,9 @@ 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@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2