sync-ruby.yml: Fix indentation

Author: k0kubun

.github/workflows/sync-ruby.yml

@@ -8,14 +8,14 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository == 'ruby/erb' }}
     steps:
-    - uses: actions/checkout@v5
+      - uses: actions/checkout@v5
 
-    - name: Create GitHub App token
-      id: app-token
-      uses: actions/create-github-app-token@v2
-      with:
-        app-id: 2060836
-        private-key: ${{ secrets.RUBY_SYNC_DEFAULT_GEMS_PRIVATE_KEY }}
+      - name: Create GitHub App token
+        id: app-token
+        uses: actions/create-github-app-token@v2
+        with:
+          app-id: 2060836
+          private-key: ${{ secrets.RUBY_SYNC_DEFAULT_GEMS_PRIVATE_KEY }}
 
       - name: Sync to ruby/ruby
         uses: convictional/trigger-workflow-and-wait@v1.6.5