Change GitHub Actions permissions to write

Author: TylerS1066

.github/workflows/gradle.yaml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     permissions:
-      contents: read
+      contents: write
       packages: write
 
     steps:
@@ -49,4 +49,4 @@ jobs:
         if: ${{ github.event_name == 'release' }}
         uses: softprops/action-gh-release@v3
         with:
-          files: staging/ModMail_${{ github.event.release.tag_name }}.jar
+          files: staging/ModMail_${{ github.event.release.tag_name }}.jar