utilize bash shell in that TF_VAR* env vars are considered

.github/workflows/terraform.yml

@@ -103,6 +103,7 @@ jobs:
           -backend-config="key=sbx-k8s-service-configuration/terraform.tfstate"
         working-directory: ./terraform/envs/${{ github.event.inputs.ENVIRONMENT }}-k8s-configuration
       - name: Install helm charts
+        shell: bash
         run: terraform apply --auto-approve
         continue-on-error: false
         working-directory: ./terraform/envs/${{ github.event.inputs.ENVIRONMENT }}-k8s-configuration