How would I be able to contact any of them in github?
So sorry for your loss, it is not only about contacting paytoshi now, paytoshi is long gone, it is about contacting specifically the person that has the private key of the bitcoin address you sent the bitcoin to. Which means, it will be hard to get your bitcoin back. Although, mistake could happen, but next time, try to check the address you are sending your bitcoin to, also check and recheck the address to be 100% certain of the recipient address.
Also know that any wallet that seem custodial, in which you have no private key to access your bitcoin on blockchain, it means the private key is managed by another party which makes it custodial, it makes you not to be the owner of the bitcoin on blockchain.
Also, transaction is not reversible. Which means your coin is gone. So sorry about this.