👷 Fix smokeshow, checkout files on CI (fastapi#1395)

Author: tiangolo

.github/workflows/smokeshow.yml

@@ -14,6 +14,7 @@ jobs:
       statuses: write
 
     steps:
+      - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
           python-version: "3.10"