explicitly specify the shell

Author: keewis

action.yaml

@@ -12,9 +12,10 @@ runs:
   using: "composite"
   steps:
     - name: install dependencies
+      shell: bash -l {0}
       run: |
         python -m pip install -r requirements.txt
-      shell: bash -l {0}
     - name: analyze environments
+      shell: bash -l {0}
       run: |
         python minimum_versions.py ${{ inputs.env-paths }}