fix(pytest_plugin): clean up docstrings for autofixture extension compatibility

why: The new sphinx_pytest_fixtures extension auto-generates "Used by"
and "Returns" fields from introspection, so hand-written duplicates
cause double rendering. Cross-references also need :fixture: role
instead of :func: to resolve against the new py:fixture domain object.
what:
- Change :func:`user_path` to :fixture:`user_path` in home_user_name
  docstring
- Remove manual "Used by: :func:`config_file`, :func:`zshrc`" from
  user_path docstring (now auto-generated)
- Remove redundant Returns section from TestServer docstring (return
  type is inferred from the annotation)

Author: tony

src/libtmux/pytest_plugin.py

@@ -32,16 +32,14 @@ def home_path(tmp_path_factory: pytest.TempPathFactory) -> pathlib.Path:
 
 @pytest.fixture(scope="session")
 def home_user_name() -> str:
-    """Return default username to set for :func:`user_path` fixture."""
+    """Return default username to set for :fixture:`user_path` fixture."""
     return getpass.getuser()
 
 
 @pytest.fixture(scope="session")
 def user_path(home_path: pathlib.Path, home_user_name: str) -> pathlib.Path:
     """Ensure and return temporary user directory.
 
-    Used by: :func:`config_file`, :func:`zshrc`
-
     Note: You will need to set the home directory, see :ref:`set_home`.
     """
     p = home_path / home_user_name
@@ -274,11 +272,6 @@ def TestServer(
     This is similar to the server pytest fixture, but can be used outside of pytest.
     The server will be killed when the test completes.
 
-    Returns
-    -------
-    type[Server]
-        A factory function that returns a Server with a unique socket_name
-
     Examples
     --------
     >>> server = Server()  # Create server instance