Fix example for S611 (#16316)

## Summary

* Existing example did not include RawSQL() call like it should
* Also clarify the example a bit to make it clearer that the code is not
secure
## Test Plan

N/A, only documentation updated

crates/ruff_linter/src/rules/flake8_bandit/rules/django_raw_sql.rs

@@ -18,7 +18,7 @@ use crate::checkers::ast::Checker;
 /// from django.db.models.expressions import RawSQL
 /// from django.contrib.auth.models import User
 ///
-/// User.objects.annotate(val=("%secure" % "nos", []))
+/// User.objects.annotate(val=RawSQL("%s" % input_param, []))
 /// ```
 ///
 /// ## References