Don't trigger workflows in unnecessary events and always use jellyfin-bot

.github/workflows/check-backport.yml

@@ -1,7 +1,10 @@
 name: Stable Backport Check
 on:
   issue_comment:
-  pull_request:
+    types:
+      - created
+      - edited
+  pull_request_target:
     types:
       - labeled
       - synchronize

.github/workflows/label-commenter.yml

@@ -20,3 +20,5 @@ jobs:
 
       - name: Label Commenter
         uses: peaceiris/actions-label-commenter@v1
+        with:
+          github_token: ${{ secrets.JF_BOT_TOKEN }}

.github/workflows/rebase.yml

@@ -1,6 +1,9 @@
 name: Automatic Rebase
 on:
   issue_comment:
+    types:
+      - created
+      - edited
 
 jobs:
   rebase: