CI: Fix workflow not being able to update a pull-request

should work now, though untested

Signed-off-by: Knut Ahlers <knut@ahlers.me>

.github/workflows/pr-regen-translations.yml

@@ -2,7 +2,12 @@
 
 name: pull-request-ci
 on:
-  pull_request:
+  pull_request_target:
+    types: ["opened", "synchronize", "reopened", "labeled", "unlabeled"]
+    branches: ["main"]
+
+permissions:
+  contents: write
 
 jobs:
   generate-translations:
@@ -18,12 +23,11 @@ jobs:
 
     runs-on: ubuntu-latest
 
-    permissions:
-      # required to push a commit
-      contents: write
-
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
 
       - name: Marking workdir safe
         run: git config --global --add safe.directory /__w/ots/ots