Fix callable type check in filter validation

Updated the type check for filter values to correctly identify callables using the `callable()` function. This ensures the validation logic behaves as expected when handling callable objects.

Author: doubledare704

fastcrud/endpoint/helper.py

@@ -55,7 +55,7 @@ class FilterConfig(BaseModel):
     @field_validator("filters")
     def check_filter_types(cls, filters: dict[str, Any]) -> dict[str, Any]:
         for key, value in filters.items():
-            if not isinstance(value, (type(None), str, int, float, bool, Callable)):
+            if not (isinstance(value, (type(None), str, int, float, bool)) or callable(value)):
                 raise ValueError(f"Invalid default value for '{key}': {value}")
         return filters
 
@@ -261,4 +261,4 @@ def filters(
     sig = inspect.Signature(params)
     setattr(filters, "__signature__", sig)
 
-    return filters
+    return filters