chore: refactor errors to use errors.Is (#3654)

core/stores/sqlx/mysql.go

@@ -1,6 +1,10 @@
 package sqlx
 
-import "github.com/go-sql-driver/mysql"
+import (
+	"errors"
+
+	"github.com/go-sql-driver/mysql"
+)
 
 const (
 	mysqlDriverName           = "mysql"
@@ -18,7 +22,8 @@ func mysqlAcceptable(err error) bool {
 		return true
 	}
 
-	myerr, ok := err.(*mysql.MySQLError)
+	var myerr *mysql.MySQLError
+	ok := errors.As(err, &myerr)
 	if !ok {
 		return false
 	}