Fix syntax for importing GSASII in workflow

Author: briantoby

.github/workflows/bilbao-test.yml

@@ -26,7 +26,7 @@ jobs:
     - name: diagnose GSAS-II issues
       run: |
           cd pixi
-          pixi run python -c import GSASII
+          pixi run python -c "import GSASII"
           pixi run python -c "import GSASII.pyspg; print(GSASII.pyspg.__file__)"
           pixi run python -c "from GSASII import GSASIIspc as G2spc; G2spc.SpcGroup('R 3 C r')"