ci: Notify in zulip when a build fails in GitHub Actions.

We use the circleci integration which already has a nice setup
for sending messages when triggered to send the build failure
notification.

.github/workflows/legacy-os.yml

@@ -16,3 +16,9 @@ jobs:
         run: |
           { { ! sudo scripts/lib/upgrade-zulip-stage-2 2>&1 >&3; } | tee upgrade.err; } 3>&1 >&2
           grep -Fq 'upgrade-zulip-stage-2: Unsupported platform: ubuntu 16.04' upgrade.err
+
+      - name: Report status
+        if: failure()
+        env:
+          ZULIP_BOT_KEY: ${{ secrets.ZULIP_BOT_KEY }}
+        run: tools/ci/send-failure-message

.github/workflows/production-suite.yml

@@ -99,6 +99,12 @@ jobs:
           path: /tmp/production-build
           retention-days: 14
 
+      - name: Report status
+        if: failure()
+        env:
+          ZULIP_BOT_KEY: ${{ secrets.ZULIP_BOT_KEY }}
+        run: tools/ci/send-failure-message
+
   production_install:
     strategy:
       fail-fast: false
@@ -142,6 +148,7 @@ jobs:
           chmod +x /tmp/production-upgrade-pg
           chmod +x /tmp/production-install
           chmod +x /tmp/production-verify
+          chmod +x /tmp/send-failure-message
 
       - name: Create cache directories
         run: |
@@ -181,3 +188,9 @@ jobs:
       - name: Verify install after upgrading postgresql
         if: ${{ matrix.is_bionic }}
         run: sudo mispipe "/tmp/production-verify 2>&1" ts
+
+      - name: Report status
+        if: failure()
+        env:
+          ZULIP_BOT_KEY: ${{ secrets.ZULIP_BOT_KEY }}
+        run: /tmp/send-failure-message

.github/workflows/zulip-ci.yml

@@ -153,7 +153,9 @@ jobs:
       - name: Check development database build
         if: ${{ matrix.is_focal }}
         run: mispipe "tools/ci/setup-backend" ts
-      # TODO: We need to port the notify_failure step from CircleCI
-      # config, however, it might be the case that GitHub notifications
-      # make this unnecessary. More details on settings to configure it:
-      # https://help.github.com/en/github/managing-subscriptions-and-notifications-on-github/configuring-notifications#github-actions-notification-options
+
+      - name: Report status
+        if: failure()
+        env:
+          ZULIP_BOT_KEY: ${{ secrets.ZULIP_BOT_KEY }}
+        run: tools/ci/send-failure-message