Switch from black to ruff (#2306)

See https://docs.astral.sh/ruff/formatter/

## Checklist

- [x] I have run Talon spoken form tests
- [-] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [-] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [x] I have not broken the cheatsheet

Author: pokey

src/marks/decorated_mark.py

@@ -23,7 +23,7 @@ def cursorless_grapheme(m) -> str:
     except AttributeError:
         # NB: This represents unknown char in Unicode.  It will be translated
         # to "[unk]" by Cursorless extension.
-        return "\uFFFD"
+        return "\ufffd"
 
 
 @mod.capture(

src/private_api/private_api.py

@@ -31,7 +31,7 @@ def cursorless_private_build_primitive_target(
         return PrimitiveTarget(mark, modifiers)
 
     def cursorless_private_build_list_target(
-        elements: list[Union[PrimitiveTarget, RangeTarget]]
+        elements: list[Union[PrimitiveTarget, RangeTarget]],
     ) -> Union[PrimitiveTarget, ListTarget]:
         """Cursorless private api low-level target builder: Create a list target"""
         if len(elements) == 1: