symtable: has_exec was removed in 3.9 (#7911)

stdlib/symtable.pyi

@@ -15,7 +15,9 @@ class SymbolTable:
     def is_optimized(self) -> bool: ...
     def is_nested(self) -> bool: ...
     def has_children(self) -> bool: ...
-    def has_exec(self) -> bool: ...
+    if sys.version_info < (3, 9):
+        def has_exec(self) -> bool: ...
+
     def get_identifiers(self) -> Sequence[str]: ...
     def lookup(self, name: str) -> Symbol: ...
     def get_symbols(self) -> list[Symbol]: ...