Error message for walrus etc. in PEP 695 contexts could be improved #104572
Description
Before:
>>> type A[T: (x:=3)] = int
File "<stdin>", line 1
SyntaxError: 'named expression' can not be used within a TypeVar bound
After:
>>> type A[T: (x:=3)] = int
File "<stdin>", line 1
SyntaxError: named expression cannot be used within a TypeVar bound
("cannot" is one word; the quotes don't really make sense here)