You should keep it. As already mentioned, it can be anytime recreated from the private key and there is nothing that could be done with this key in case it would get to "bad people". They can already download it from your github or someplace else.
What is worth mentioning, the OpenSSH can make use of this separately stored public key in case the private is encrypted. In that case, it can try the public key without asking you for a passphrase of that private one.
Without this key, OpenSSH would ask you for a passphrase for every connection (even to other servers) if the key is in one of the default locations.