ci: pull_request_target → pull_request

Revert "ci: pull_request_target → pull_request"

since reviewdog passing status is not required.
i.e. PR can be merged without reviewdog status passed

.github/workflows/reviewdog.yml

@@ -1,11 +1,13 @@
 name: reviewdog
-on: [pull_request]
+on: [pull_request_target]
 jobs:
   reviewdog:
     name: reviewdog
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
       - uses: actions/setup-go@v5
         with:
           go-version: '1.22'