fix: trigger E301 on decorated methods.

fixes astral-sh#10114

crates/ruff_linter/src/rules/pycodestyle/rules/blank_lines.rs

@@ -658,8 +658,10 @@ impl BlankLinesChecker {
         if self.is_not_first_logical_line {
             if line.preceding_blank_lines == 0
                 // Only applies to methods.
-                && matches!(line.kind,  LogicalLineKind::Function)
-                && matches!(self.class_status, Status::Inside(_))
+                && matches!(line.kind,  LogicalLineKind::Function | LogicalLineKind::Decorator)
+                // Allow groups of one-liners.
+                && !(matches!(state.follows, Follows::Def) && !matches!(line.last_token, TokenKind::Colon))
+                && matches!(state.class_status, Status::Inside(_))
                 // The class/parent method's docstring can directly precede the def.
                 // Allow following a decorator (if there is an error it will be triggered on the first decorator).
                 && !matches!(self.follows, Follows::Docstring | Follows::Decorator)