Fix walrus assignment type propagation in call arguments

Author: Vaishnavi KN

assignment inference test

@@ -0,0 +1,15 @@
+diff --git a/test-data/unit/check-expressions.test b/test-data/unit/check-expressions.test
+index 4d99325d9..0e01e6bbc 100644
+--- a/test-data/unit/check-expressions.test
++++ b/test-data/unit/check-expressions.test
+@@ -2540,6 +2540,10 @@ def last_known_value() -> None:
+ [builtins fixtures/primitives.pyi]
+ 
+ [case walrus_operator_in_comprehension_infers_type]
++# Ensure that assignment expressions (:=) inside comprehensions
++# correctly infer and propagate the assigned variable's type
++# outside the comprehension scope.
++
+ from dataclasses import dataclass
+ 
+ @dataclass