pypi: don't use it just as a fallback for new versions

In case Arch and pypi both had the package we would prefer Arch.
While that helps in case Arch tries to keep older versions to keep
everything compatible, there are cases where things are outdated
in Arch and updates happend despite being in conflict,
so in reality we need to check ourselves anyway.

app/fetch/pypi.py

@@ -51,4 +51,4 @@ async def update_pypi_versions(pkgextra: PkgExtra) -> None:
             pypi_versions[pypi_name] = ExtInfo(
                 pypi_name, info["version"], oldest_timestamp, info["project_url"], {})
 
-    state.set_ext_infos(ExtId("pypi", "PyPI", True), pypi_versions)
+    state.set_ext_infos(ExtId("pypi", "PyPI", False), pypi_versions)