Fix a bunch of deepsource warnings (#11814)

crypto/bls/blst/secret_key_test.go

@@ -88,7 +88,7 @@ func TestSerialize(t *testing.T) {
 
 func TestZeroKey(t *testing.T) {
 	// Is Zero
-	zKey := [32]byte{}
+	var zKey [32]byte
 	assert.Equal(t, true, blst.IsZero(zKey[:]))
 
 	// Is Not Zero

crypto/bls/signature_batch_test.go

@@ -703,7 +703,7 @@ func NewInvalidSignatureSet(t *testing.T, msgBody string, num int, throwErr bool
 }
 
 func messageBytes(message string) [32]byte {
-	bytes := [32]byte{}
+	var bytes [32]byte
 	copy(bytes[:], []byte(message))
 	return bytes
 }