errors: fix typo in TODO comment

Fixes #34846
Change-Id: I24b3e65fc96ec85b2821480e9396c9d1663611c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/200678
Run-TryBot: Johan Brandhorst <johan.brandhorst@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Johan Brandhorst <johan.brandhorst@gmail.com>

src/errors/wrap.go

@@ -49,7 +49,7 @@ func Is(err, target error) bool {
 		if x, ok := err.(interface{ Is(error) bool }); ok && x.Is(target) {
 			return true
 		}
-		// TODO: consider supporing target.Is(err). This would allow
+		// TODO: consider supporting target.Is(err). This would allow
 		// user-definable predicates, but also may allow for coping with sloppy
 		// APIs, thereby making it easier to get away with them.
 		if err = Unwrap(err); err == nil {