Update PR action (#3774)

- upgrade Java action to resolve deprecation warnings
- `Kas-tle/ForkFinder`is now `Kas-tle/find-forks-action`

.github/workflows/pullrequest.yml

@@ -17,13 +17,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up JDK 17
-        uses: actions/setup-java@v1
+        uses: actions/setup-java@v3
         with:
           java-version: 17
           distribution: temurin
 
       - name: Check if the author has forked the API repo
-        uses: Kas-tle/ForkFinder@v1.0.1
+        uses: Kas-tle/find-forks-action@v1.0.1
         id: find_forks
         with:
           owner: GeyserMC