lint fix

Author: Karthikeyannhs

src/eligibility_signposting_api/model/rules.py

@@ -102,7 +102,8 @@ class IterationRule(BaseModel):
     rule_stop: bool = Field(default=False, alias="RuleStop")
 
     @field_validator("rule_stop", mode="before")
-    def parse_yn_to_bool(cls, v: str | bool) -> bool:  # noqa: N805
+    @staticmethod
+    def parse_yn_to_bool(v: str | bool) -> bool:
         if isinstance(v, str):
             return v.upper() == "Y"
         return bool(v)