Formatter quoting for f-strings with triple quotes (#7826)

**Summary** Quoting of f-strings can change if they are triple quoted
and only contain single quotes inside.

Fixes #6841

**Test Plan** New fixtures

---------

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>

crates/ruff_python_formatter/tests/snapshots/format@expression__fstring.py.snap

@@ -63,6 +63,11 @@ result_f = (
     ),
     2
 )
+
+# https://github.com/astral-sh/ruff/issues/6841
+x = f'''a{""}b'''
+y = f'''c{1}d"""e'''
+z = f'''a{""}b''' f'''c{1}d"""e'''
 ```
 
 ## Output
@@ -124,6 +129,11 @@ result_f = (
     ),
     2,
 )
+
+# https://github.com/astral-sh/ruff/issues/6841
+x = f"""a{""}b"""
+y = f'''c{1}d"""e'''
+z = f"""a{""}b""" f'''c{1}d"""e'''
 ```