syntax error fix

Author: MekDrop

action.yml

@@ -65,7 +65,7 @@ runs:
     - name: Generating generator config...
       env:
         ACTION_PATH: ${{ github.action_path }}
-        PHPDOCMD_FILE: ${{ env.$COPY_DATA_PATH }}/.phpdoc-md
+        PHPDOCMD_FILE: ${{ env.COPY_DATA_PATH }}/.phpdoc-md
         CLASS_ROOT_NAMESPACE: ${{ inputs.class_root_namespace }}
         DOCS_PATH: ${{ inputs.output_path }}
       run: php $ACTION_PATH/generate-config.php "$PHPDOCMD_FILE" "$PHP_CLASSES_FILTERED_FILE" "$CLASS_ROOT_NAMESPACE" "$DOCS_PATH"