ci: fix pull request workflow

Author: ObserverOfTime

.github/workflows/pr.yml

@@ -14,6 +14,10 @@ jobs:
   pull-request:
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
       - name: Create app token
         uses: actions/create-github-app-token@v2
         id: app-token
@@ -25,6 +29,5 @@ jobs:
           gh pr create -d -B master -H "$GITHUB_REF_NAME"
           "${PR_TITLE:+--title=}${PR_TITLE:---fill-first}"
         env:
-          GH_REPO: ${{github.repository}}
           GH_TOKEN: ${{steps.app-token.outputs.token}}
           PR_TITLE: ${{github.event.inputs.title}}