Remove support for Google Spanner database. (#105846)

* Remove support for Google Spanner database.

pkg/infra/db/db.go

@@ -54,7 +54,6 @@ type InitTestDBOpt = sqlstore.InitTestDBOpt
 var SetupTestDB = sqlstore.SetupTestDB
 var CleanupTestDB = sqlstore.CleanupTestDB
 var ProvideService = sqlstore.ProvideService
-var SkipTestsOnSpanner = sqlstore.SkipTestsOnSpanner
 
 func InitTestDB(t sqlutil.ITestDB, opts ...InitTestDBOpt) *sqlstore.SQLStore {
 	db, _ := InitTestDBWithCfg(t, opts...)
@@ -96,11 +95,3 @@ func IsTestDBMSSQL() bool {
 
 	return false
 }
-
-func IsTestDBSpanner() bool {
-	if db, present := os.LookupEnv("GRAFANA_TEST_DB"); present {
-		return db == migrator.Spanner
-	}
-
-	return false
-}

pkg/infra/serverlock/serverlock.go

@@ -374,10 +374,6 @@ func (sl *ServerLockService) createLock(ctx context.Context,
 		}
 		lockRow.Id = id
 	} else {
-		if sl.SQLStore.GetDBType() == migrator.Spanner {
-			rawSQL += " THEN RETURN id" // Required for successful LastInsertId call.
-		}
-
 		res, err := dbSession.Exec(
 			rawSQL,
 			lockRow.OperationUID, lockRow.LastExecution, 0)