The structure of the error is changing, and we don't guarantee
reflect.DeepEqual(...) will remain true for ErrWaitTimeout currently.
Kubernetes-commit: 8d4004bbc77d012642db97e09238f4f65a926bca
Currently, watch package embeds context deadlineexceeded error
in it's own error using `%v`, as can be seen in here;
`fmt.Errorf("UntilWithSync: unable to sync caches: %v", ctx.Err())`
However, consumers of this function can not use
`errors.Is(err, context.DeadlineExceeded)` due this `%v`.
To let consumers can distinguish context deadlineexceeded errors,
this PR changes error embedding format to `%w`.
Kubernetes-commit: 6b7c365f8f6d50280c2dab171efdd4b93d964f32
