sync: update CI config files (#241)

* bump go.mod to Go 1.17 and run go fix

* update .github/workflows/automerge.yml

* update .github/workflows/go-test.yml

* update .github/workflows/go-check.yml

* remove unneeded nil check in ECDSAPublicKey.Verify

Co-authored-by: web3-bot <web3-bot@users.noreply.github.com>
Co-authored-by: Marten Seemann <martenseemann@gmail.com>

core/crypto/ecdsa.go

@@ -162,9 +162,6 @@ func (ePub *ECDSAPublicKey) Verify(data, sigBytes []byte) (bool, error) {
 	if _, err := asn1.Unmarshal(sigBytes, sig); err != nil {
 		return false, err
 	}
-	if sig == nil {
-		return false, ErrNilSig
-	}
 
 	hash := sha256.Sum256(data)