Add _lastModified column to d_b_workspace_cluster

So that it can be synced with `db-sync.`

Author: Andrew Farries

Diff for: components/gitpod-db/src/typeorm/entity/db-workspace-cluster.ts

@@ -14,6 +14,7 @@ import {
 import { ValueTransformer } from "typeorm/decorator/options/ValueTransformer";
 
 @Entity()
+// on DB but not Typeorm: @Index("ind_lastModified", ["_lastModified"])   // DBSync
 export class DBWorkspaceCluster implements WorkspaceCluster {
     @PrimaryColumn()
     name: string;

Diff for: components/gitpod-db/src/typeorm/migration/1666616345054-AddLastModifiedToWorkspaceClusterTable.ts

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) 2022 Gitpod GmbH. All rights reserved.
+ * Licensed under the GNU Affero General Public License (AGPL).
+ * See License-AGPL.txt in the project root for license information.
+ */
+
+import { MigrationInterface, QueryRunner } from "typeorm";
+
+const TABLE_NAME = "d_b_workspace_cluster";
+const COLUMN_NAME = "_lastModified";
+const INDEX_NAME = "ind_lastModified";
+
+export class AddLastModifiedToWorkspaceClusterTable1666616345054 implements MigrationInterface {
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(
+            `ALTER TABLE ${TABLE_NAME} ADD COLUMN ${COLUMN_NAME} timestamp(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6), ALGORITHM=INPLACE, LOCK=NONE `,
+        );
+        queryRunner.query(`CREATE INDEX ${INDEX_NAME} ON ${TABLE_NAME} (${COLUMN_NAME})`);
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {}
+}