redis: Restore type annotations of ping() and save() (#6720)

stubs/redis/redis/commands/core.pyi

@@ -112,10 +112,10 @@ class ManagementCommands:
     def memory_malloc_stats(self, **kwargs): ...
     def memory_usage(self, key, samples: Any | None = ..., **kwargs): ...
     def memory_purge(self, **kwargs): ...
-    def ping(self, **kwargs): ...
+    def ping(self, **kwargs) -> bool: ...
     def quit(self, **kwargs): ...
     def replicaof(self, *args, **kwargs): ...
-    def save(self, **kwargs): ...
+    def save(self, **kwargs) -> bool: ...
     def shutdown(self, save: bool = ..., nosave: bool = ..., **kwargs) -> None: ...
     def slaveof(self, host: Any | None = ..., port: Any | None = ..., **kwargs): ...
     def slowlog_get(self, num: Any | None = ..., **kwargs): ...