Revert #6114

Frozen kitty builds dont have python files (they are loaded from a
single mmmaped archive), so the test will prevent any
kittens from being found.

Have make clean remove leftover kittens directories

kittens/runner.py

@@ -133,7 +133,7 @@ def run_kitten(kitten: str, run_name: str = '__main__') -> None:
 def all_kitten_names() -> FrozenSet[str]:
     ans = []
     for name in list_kitty_resources('kittens'):
-        if '__' not in name and '.' not in name and 'main.py' in list_kitty_resources(f'kittens.{name}'):
+        if '__' not in name and '.' not in name and name != 'tui':
             ans.append(name)
     return frozenset(ans)