Revert "build: Move "Test plugin upgrades" to a post-build workflow"

.github/workflows/build.yml

@@ -128,6 +128,56 @@ jobs:
               comment_id: +COMMENT_ID,
             } );
 
+  upgrade_test:
+    name: Test plugin upgrades
+    runs-on: ubuntu-latest
+    needs: build
+    if: needs.build.outputs.any_plugins == 'true'
+    timeout-minutes: 10  # 2022-03-04: Successful runs seem to take about 3 minutes, but give some extra time for the downloads.
+    services:
+      db:
+        image: mariadb:latest
+        env:
+          MARIADB_ROOT_PASSWORD: wordpress
+        ports:
+          - 3306:3306
+        options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=5
+    container:
+      image: ghcr.io/automattic/jetpack-wordpress-dev:latest
+      env:
+        WP_DOMAIN: localhost
+        WP_ADMIN_USER: wordpress
+        WP_ADMIN_EMAIL: [email protected]
+        WP_ADMIN_PASSWORD: wordpress
+        WP_TITLE: Hello World
+        MYSQL_HOST: db:3306
+        MYSQL_DATABASE: wordpress
+        MYSQL_USER: root
+        MYSQL_PASSWORD: wordpress
+        HOST_PORT: 80
+      ports:
+        - 80:80
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          path: monorepo
+
+      - name: Download build artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: jetpack-build
+      - name: Extract build archive
+        run: tar --xz -xvvf build.tar.xz
+
+      - name: Setup WordPress
+        run: monorepo/.github/files/test-plugin-update/setup.sh
+
+      - name: Prepare plugin zips
+        run: monorepo/.github/files/test-plugin-update/prepare-zips.sh
+
+      - name: Test upgrades
+        run: monorepo/.github/files/test-plugin-update/test.sh
+
   jetpack_beta:
     name: Create artifact for Jetpack Beta plugin
     runs-on: ubuntu-latest

.github/workflows/slack-workflow-failed.yml

@@ -7,7 +7,6 @@ on:
       - Build Docker
       - Tests
       - Gardening
-      - Post-Build
       - PR is up-to-date
     branches: [ 'trunk', '*/branch-*' ]