chore: don't sync example from v4 branch

.github/sync.yml

@@ -1,7 +0,0 @@
-# This is a legacy example pushed from the v4 branch
-nextauthjs/next-auth-example:
-  - source: apps/example-nextjs
-    dest: .
-    deleteOrphaned: true
-  - .github/FUNDING.yml
-  - LICENSE

.github/workflows/sync-examples.yml

@@ -1,18 +0,0 @@
-name: Sync Example Repositories
-on:
-  push:
-    branches:
-      - v4
-  workflow_dispatch:
-jobs:
-  sync:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout Repository
-        uses: actions/checkout@v3
-      - name: Run GitHub File Sync
-        # Can update to v1 when https://github.com/BetaHuhn/repo-file-sync-action/issues/168 is resolved
-        uses: BetaHuhn/repo-file-sync-action@v1.16.5
-        with:
-          GH_PAT: ${{ secrets.GH_PAT_CLASSIC }}
-          SKIP_PR: true