conditional apt-get

Author: swissspidy

.github/workflows/testing.yml

@@ -256,6 +256,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Install Ghostscript
+        if: ${{ matrix.os == 'ubuntu-22.04' || matrix.os == '' }}
         run: |
           sudo apt-get update
           sudo apt-get install ghostscript -y