Refactor test case for generic type alias unpacking

Removed xfail marker from test case and updated comments for clarity.

Author: hyperkai

test-data/unit/check-type-aliases.test

@@ -1237,18 +1237,17 @@ Ta2 = TypeAliasType("Ta2", None, type_params=(Unpack[Ts],))  # E: Free type vari
 
 [builtins fixtures/tuple.pyi]
 
-[case testGenericTypeAliasArgOfTypeAliasIsUnpackedTuple-xfail]
+[case testGenericTypeAliasArgOfTypeAliasIsUnpackedTuple]
 from typing_extensions import TypeAlias
 from typing import TypeVarTuple, Unpack
 
 Ts = TypeVarTuple('Ts')
 
 TA: TypeAlias = tuple[Unpack[Ts]]
 
-# For Python 3.10, error: Invalid syntax
-# For other Python, error: "list[int]" cannot be unpacked (must be tuple or TypeVarTuple)
-v1: TA[*list[int]]
-v2: TA[Unpack[list[int]]]
+v1: TA[*list[int]]         # E: "list[int]" cannot be unpacked (must be tuple or TypeVarTuple)
+v2: TA[Unpack[list[int]]]  # E: "list[int]" cannot be unpacked (must be tuple or TypeVarTuple)
+# python3.10: Invalid syntax
 [builtins fixtures/tuple.pyi]
 
 [case testAliasInstanceNameClash]