Skip noop migrations, instead of executing SELECT 0. (#103086)

* Skip noop migrations, instead of executing SELECT 0.

pkg/services/sqlstore/migrator/dialect.go

@@ -74,7 +74,6 @@ type Dialect interface {
 
 	CleanDB(engine *xorm.Engine) error
 	TruncateDBTables(engine *xorm.Engine) error
-	NoOpSQL() string
 	// CreateDatabaseFromSnapshot is called when migration log table is not found.
 	// Dialect can recreate all tables from existing snapshot. After successful (nil error) return,
 	// migrator will list migrations from the log, and apply all missing migrations.
@@ -353,10 +352,6 @@ func (b *BaseDialect) CreateDatabaseFromSnapshot(ctx context.Context, engine *xo
 	return nil
 }
 
-func (b *BaseDialect) NoOpSQL() string {
-	return "SELECT 0;"
-}
-
 func (b *BaseDialect) TruncateDBTables(engine *xorm.Engine) error {
 	return nil
 }