ruff server does not merge editor settings with fallback settings

[snowsignal]

If no file-based configuration exists for a workspace, only the fallback settings are used, and they are not combined with editor settings. The expected behavior is that editor settings should still be merged with fallback settings.

[akthe-at]

@snowsignal Does this PR solve this scenario:
Windows 10
Neovim Nightly Latest
Ruff 0.4.3
Python 3.12.3

• Have global config in ~/.config/ruff/pyproject.toml
• Create "test.py" in ~/ (not a project/workspace and there is no present .toml config)
• Create a test function

def this_function(y: int, x: int) -> int:


    """ This is an example function """


    word_fx: int = 0
    return y + x + word_fx

• Notice the excessive space between function definition and doc strings...
• Attempt to save (my neovim config would use conform.nvim to call ruff to format on save)
• 2-4 second hang...ruff errors and times out (  Warn 8:53:50 PM notify.warn [LSP][ruff] timeout)
• Curve ball...wait a minute or two to type this example/report up...go to save and it formats successfully this time.
• This does not occur in projects with a local .toml file...
• I am assuming this is because it takes time to look for the global config and it doesn't merge with the editor config without the local config?