Remove pytest.ini from project detection files

This breaks detecting the project root when editing tests with a nested
pytest.ini file where other project files are available. The other files
are so common we can just removes this entirely and test that we
ignore it in one case.

doc/ale-python.txt

@@ -63,7 +63,6 @@ ALE will look for configuration files with the following filenames. >
 
   MANIFEST.in
   setup.cfg
-  pytest.ini
   tox.ini
   .pyre_configuration.local
   mypy.ini
@@ -81,6 +80,7 @@ ALE will look for configuration files with the following filenames. >
   poetry.lock
   pyproject.toml
   .tool-versions
+  uv.lock
 <
 
 The first directory containing any of the files named above will be used.