feat: Add cat_file step to read cache configuration for save_cache

Author: AtomicFS

action.yml

@@ -139,11 +139,17 @@ runs:
         INPUT_TARGET: ${{ inputs.target }}
         INPUT_RECURSIVE: ${{ inputs.recursive }}
 
+    - id: cat_file
+      if: always()
+      shell: bash
+      run: |
+        echo "content=$(cat .firmware-action/cache-dirs.json)" >> "${GITHUB_OUTPUT}"
+
     - name: save_cache
       if: always()
       uses: actions/cache/save@v4
       with:
         path: |
-          ${{ fromJSON( cat '.firmware-action/cache-dirs.json' ).paths }}
+          ${{ fromJSON(steps.cat_file.outputs.content).paths }}
         key: firmware-action-${{ hashFiles(inputs.config) }}