Fix tests-full failure to checkout PR branch (#253)

Author: ultmaster

.github/workflows/tests-full.yml

@@ -46,7 +46,7 @@ jobs:
         run: nvidia-smi
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.number && format('refs/pull/{0}/merge', github.event.pull_request.number) || github.ref }}
+          ref: ${{ github.event_name == 'repository_dispatch' && github.event.client_payload.pr_ref || (github.event.pull_request.number && format('refs/pull/{0}/merge', github.event.pull_request.number)) || github.ref }}
       - uses: astral-sh/setup-uv@v7
         with:
           enable-cache: true