fix: change yml to yaml

.github/workflows/sync-labels.yaml

@@ -0,0 +1,28 @@
+# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json
+
+name: Sync labels
+
+on:
+  workflow_call:
+    secrets:
+      GITHUB_TOKEN:
+        description: 'GitHub token'
+        required: true
+
+permissions:
+  contents: read
+  issues: write
+
+jobs:
+  main:
+    name: Sync labels
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: ⤵️ Check out code from GitHub
+        uses: actions/checkout@v4
+
+      - name: 🚀 Run Label Syncer
+        uses: micnncim/action-label-syncer@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}