use bash to set the env var

Author: evertlammerts

.github/workflows/packaging_wheels.yml

@@ -73,6 +73,7 @@ jobs:
 
       # Make sure that OVERRIDE_GIT_DESCRIBE is propagated to cibuildwhel's env, also when it's running linux builds
       - name: Set OVERRIDE_GIT_DESCRIBE
+        shell: bash
         if: ${{ inputs.set-version != '' }}
         run: echo "CIBW_ENVIRONMENT=OVERRIDE_GIT_DESCRIBE=${{ inputs.set-version }}" >> $GITHUB_ENV