Support notify_is_valid_token to allow Go 1.20+ binaries to run on older than 10.10

[krackers]

​https://github.com/golang/go/commit/76d39ae3499238ac7efb731f4f4cd47b1b3288ab seems to add a call to notify_is_valid_token, and the reasoning for doing so is apparently to work around some bug in exec(), as described in ​https://go-review.googlesource.com/c/go/+/451735/3//COMMIT_MSG#49

It's not clear if the bug that's being worked around existed on older osx versions as well. Polyfilling this function seems quite difficult as it accesses a lot of internal state of libnotify. (It's theoretically possible to do this of course, since libnotify is open source and we can see the implementation, but it would require a lot of runtime hijinks to get the address of hidden visibility symbols).

Probably the easier approach is patching Go itself.