GitHub already has a program to scan for keys, since publishing Discord tokens by mistake used to get the token immediately revoked and a DM from the system account saying why

I thought there were many first and third party services looking for this kind of thing (AWS, Github, GWS, crypto, etc tokens). Seems weird that a F500 company repo was not receiving the regular, let alone extra deep scanning which could have trivially found these.

There was a recent post from someone who made the realization that most of these scanning services only investigate the main branch. Extra gold in them hills if you also consider development branches.