test: stabilize clean checkout validation

Author: kadevin

.public-export-manifest.json

@@ -22,6 +22,7 @@
     "scripts/build-update-manifest.py",
     "scripts/build-webui-css.mjs",
     "scripts/migrate-webui-source-data.py",
+    "scripts/run-webui-provider-fixture.py",
     "tests",
     "tsconfig.webui.json"
   ],