## Summary
Fixes https://github.com/astral-sh/ruff/issues/11158.
A settings file in the ruff user configuration directory will be used as
a configuration fallback, if it exists.
## Test Plan
Create a `pyproject.toml` or `ruff.toml` configuration file in the ruff
user configuration directory.
* On Linux, that will be `$XDG_CONFIG_HOME/ruff/` or `$HOME/.config`
* On macOS, that will be `$HOME/Library/Application Support`
* On Windows, that will be `{FOLDERID_LocalAppData}`
Then, open a file inside of a workspace with no configuration. The
settings in the user configuration file should be used.
068e22d382