accept new unsupported syntax errors

Author: ntBre

crates/ruff_python_formatter/tests/snapshots/black_compatibility@cases__fstring.py.snap

@@ -72,3 +72,17 @@ f'Hello \'{tricky + "example"}\''
 f"Tried directories {str(rootdirs)} \
 but none started with prefix {parentdir_prefix}"
 ```
+
+## New Unsupported Syntax Errors
+
+error[invalid-syntax]: Cannot reuse outer quote character in f-strings on Python 3.10 (syntax was added in Python 3.12)
+ --> fstring.py:6:9
+  |
+4 | f"some f-string with {a} {few():.2f} {formatted.values!r}"
+5 | f"some f-string with {a} {few(''):.2f} {formatted.values!r}"
+6 | f"{f'''{"nested"} inner'''} outer"
+  |         ^
+7 | f'"{f"{nested} inner"}" outer'
+8 | f"space between opening braces: { {a for a in (1, 2, 3)} }"
+  |
+warning: Only accept new syntax errors if they are also present in the input. The formatter should not introduce syntax errors.