I'm pretty sure there is https://pkg.go.dev/crypto/ecdsa#Verify
In this case you really don't need a DER calibre encoding either, you just need a standard in the first place. It’s just that the standard would historically likely use asn.1. But that doesn't have to be the case. Maybe the closest thing is the ECDSA point form specified in https://www.secg.org/sec1-v2.pdf#page16. The the curve domain parameters in sec2 are, you guessed it, specified in asn.1.