chore: add stricter typing to construct assume role policy function (#2965)

Author: pradrx

samtranslator/model/iam.py

@@ -33,7 +33,7 @@ class IAMManagedPolicy(Resource):
 
 class IAMRolePolicies:
     @classmethod
-    def construct_assume_role_policy_for_service_principal(cls, service_principal):  # type: ignore[no-untyped-def]
+    def construct_assume_role_policy_for_service_principal(cls, service_principal: str) -> Dict[str, Any]:
         return {
             "Version": "2012-10-17",
             "Statement": [

samtranslator/model/stepfunctions/events.py

@@ -63,7 +63,7 @@ def _construct_role(self, resource, permissions_boundary=None, prefix=None, suff
         """
         role_logical_id = self._generate_logical_id(prefix=prefix, suffix=suffix, resource_type="Role")  # type: ignore[no-untyped-call]
         event_role = IAMRole(role_logical_id, attributes=resource.get_passthrough_resource_attributes())
-        event_role.AssumeRolePolicyDocument = IAMRolePolicies.construct_assume_role_policy_for_service_principal(  # type: ignore[no-untyped-call]
+        event_role.AssumeRolePolicyDocument = IAMRolePolicies.construct_assume_role_policy_for_service_principal(
             self.principal
         )
         state_machine_arn = resource.get_runtime_attr("arn")