use powershell

Author: nijel

.github/workflows/setup.yml

@@ -49,7 +49,6 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install Gammu
-        shell: bash
         run: |
           ./Gammu-1.43.0-Windows.exe /S /D=C:/Gammu
       - uses: astral-sh/setup-uv@eac588ad8def6316056a12d4907a9d4d84ff7a3b # v7.3.0