Merge pull request #4 from yokawasa/use-pull_request_target

fix: use pull_request_target for labeler to support fork PRs

Author: nnandan-postman

.github/workflows/pr-labeler.yml

@@ -1,7 +1,7 @@
 name: PR Labeler
 
 on:
-  pull_request:
+  pull_request_target:
     types: [opened, synchronize, reopened]
 
 permissions: