Added missing shell property to composite action

Author: jessevz

.github/actions/start-hashtopolis/action.yml

@@ -7,5 +7,7 @@ runs:
     - name: Start application containers
       working-directory: .devcontainer
       run: docker compose up -d
+      shell: bash
     - name: Wait until entrypoint is finished and Hashtopolis is started
-      run: bash .github/scripts/await-hashtopolis-startup.sh
+      run: bash .github/scripts/await-hashtopolis-startup.sh
+      shell: bash