ci: Switch to fork of git-sync

[1] wei/git-sync#37

Author: Frederick888

.github/workflows/repo-sync.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: repo-sync
-      uses: wei/git-sync@v3
+      uses: Frederick888/git-sync@master
       with:
         source_repo: "https://github.com/Frederick888/php-bencode.git"
         source_branch: "refs/remotes/source/*"
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: repo-sync
-      uses: wei/git-sync@v3
+      uses: Frederick888/git-sync@master
       with:
         source_repo: "https://github.com/Frederick888/php-bencode.git"
         source_branch: "refs/tags/*"