(20241218) Tags bug fix.

models/api/finstitutions/payments/request.py

@@ -188,7 +188,7 @@ class PGPaymentRequestData(BaseModel):
         frozen = True
     )
 
-    tags: List[Any] = Field(
+    tags: List[Any] | None = Field(
         description = "any no. of tags to apply to this payment record to make search and filtering easy later",
         default = None
     )
@@ -218,7 +218,7 @@ class PGPaymentRequestData(BaseModel):
         if currency is None: raise ValueError("invalid currency code, please use iso 4217 standard")
         return value
 
-    @field_validator("tags", mode = "before")
+    @field_validator("tags", mode = "after")
     def null_to_empty_list(cls, value):
         return [] if value is None else value