Merge pull request #1 from nisel11/checkout-fix

workflow: Use ref from 'branch' input in checkout

.github/workflows/mksunnyos.yml

@@ -16,6 +16,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.inputs.branch }}
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3