[flake8-logging-format] Fix invalid formatting value in docs of logging-extra-attr-clash (G101) (#14165)

Author: sbrugman

crates/ruff_linter/src/rules/flake8_logging_format/violations.rs

@@ -432,7 +432,7 @@ impl AlwaysFixableViolation for LoggingWarn {
 ///
 /// username = "Maria"
 ///
-/// logging.info("Something happened", extra=dict(user=username))
+/// logging.info("Something happened", extra=dict(user_id=username))
 /// ```
 ///
 /// ## Options