Merge pull request #18 from autowarefoundation/fix/pr-preview-labeled-event

fix(ci): set explicit action for pr-preview on labeled event

Author: atsushi421

.github/workflows/build-docs.yaml

@@ -41,6 +41,7 @@ jobs:
       - uses: rossjrw/pr-preview-action@v1
         with:
           source-dir: ./site/
+          action: deploy
 
   cleanup:
     if: github.event.action == 'closed'