try conda as mdanalysis-install installer

Author: orbeckst

.github/workflows/gh-ci.yaml

@@ -72,7 +72,7 @@ jobs:
       with:
         version: ${{ matrix.mdanalysis-version }}
         install-tests: true
-        installer:  mamba 
+        installer:  conda 
         shell: bash  -l {0} 
 
     - name: Install package