fix ValidatedString after validator

bioimageio/spec/_internal/url.py

@@ -123,12 +123,14 @@ class HttpUrl(RootHttpUrl):
     root_model: ClassVar[Type[RootModel[Any]]] = RootModel[pydantic.HttpUrl]
     _exists: Optional[bool] = None
 
-    @model_validator(mode="after")
-    def _validate(self):
-        url = self._validated
+    def _after_validator(self):
+        super()._after_validator()
         context = validation_context_var.get()
-        if context.perform_io_checks and str(url) not in context.known_files:
-            self._validated = _validate_url(url)
+        if (
+            context.perform_io_checks
+            and str(self._validated) not in context.known_files
+        ):
+            self._validated = _validate_url(self._validated)
             self._exists = True
 
         return self

bioimageio/spec/_internal/validated_string.py

@@ -6,6 +6,7 @@
     CoreSchema,
     no_info_after_validator_function,
 )
+from typing_extensions import Self
 
 
 class ValidatedString(str):
@@ -18,6 +19,10 @@ class ValidatedString(str):
     def __new__(cls, object: object):
         self = super().__new__(cls, object)
         self._validated = cls.root_model.model_validate(str(self)).root
+        return self._after_validator()
+
+    def _after_validator(self) -> Self:
+        """add validation after the `root_model`"""
         return self
 
     @classmethod