_json: Type indent as str | None (#14398)

stdlib/_json.pyi

@@ -11,7 +11,7 @@ class make_encoder:
     @property
     def key_separator(self) -> str: ...
     @property
-    def indent(self) -> int | None: ...
+    def indent(self) -> str | None: ...
     @property
     def markers(self) -> dict[int, Any] | None: ...
     @property
@@ -25,7 +25,7 @@ class make_encoder:
         markers: dict[int, Any] | None,
         default: Callable[[Any], Any],
         encoder: Callable[[str], str],
-        indent: int | None,
+        indent: str | None,
         key_separator: str,
         item_separator: str,
         sort_keys: bool,