Use Display for formatter parse errors (#9316)

## Summary

This helps a bit with (but does not close) the issues described in
https://github.com/astral-sh/ruff/issues/9311. E.g., now, we at least
see: `error: Failed to format main.py: source contains syntax errors:
invalid syntax. Got unexpected token '=' at byte offset 20`.

crates/ruff_python_formatter/src/lib.rs

@@ -108,9 +108,9 @@ where
 
 #[derive(Error, Debug)]
 pub enum FormatModuleError {
-    #[error("source contains syntax errors: {0:?}")]
+    #[error("source contains syntax errors: {0}")]
     LexError(LexicalError),
-    #[error("source contains syntax errors: {0:?}")]
+    #[error("source contains syntax errors: {0}")]
     ParseError(ParseError),
     #[error(transparent)]
     FormatError(#[from] FormatError),