feat: remove label syncer

Author: moe-ad

.github/labeler.yml

@@ -15,12 +15,4 @@ dependencies:
 CI/CD:
 - docker/**/*
 - .github/**/*
-- .ci/**/*
-
-# HACK: the label is declared with the only purpose of avoiding the
-# GitHub labeler bot from removing it. This is a known issue reported in the
-# official action/labeler repo https://github.com/actions/labeler/issues/763
-'deploy-pr-doc':
-  - all:
-      - changed-files:
-          - all-globs-to-all-files: ['THIS-NEVER-MATCHES-A-FILE']
+- .ci/**/*

.github/labels.yml

@@ -16,13 +16,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - uses: actions/checkout@v4
-
-    - name: "Sync labels"
-      uses: micnncim/action-label-syncer@3abd5ab72fda571e69fffd97bd4e0033dd5f495c # v1.3.0
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
     # Label based on modified files
     - name: "Label based on changed files"
       uses: actions/labeler@v4