Automatically notify the slack channel when tests fail (#509)

Adds a job that will automatically run at the end of the daily, which
will collect all the failed tests and send them to the developer slack.
It will include a link to the job as well.

Example job that ran on my private repo:
https://github.com/madolson/valkey/actions/runs/9123245899/job/25085418567

Example notification: 
<img width="662" alt="image"
src="https://github.com/valkey-io/valkey/assets/34459052/69127db4-e416-4321-bc06-eefcecab1130">
(Note: I removed the sassy text at the bottom from the PR)

Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>

.github/workflows/daily.yml

@@ -1073,3 +1073,35 @@ jobs:
     - name: validator
       run: ./utils/req-res-log-validator.py --verbose --fail-missing-reply-schemas ${{ (!contains(github.event.inputs.skiptests, 'valkey') && !contains(github.event.inputs.skiptests, 'module') && !contains(github.event.inputs.sentinel, 'valkey') && !contains(github.event.inputs.skiptests, 'cluster')) && github.event.inputs.test_args == '' && github.event.inputs.cluster_test_args == '' && '--fail-commands-not-all-hit' || '' }}
 
+  notify-about-job-results:
+    runs-on: ubuntu-latest
+    if: always() && github.event_name != 'workflow_dispatch' && github.repository == 'valkey-io/valkey'
+    needs: [test-ubuntu-jemalloc, test-ubuntu-jemalloc-fortify, test-ubuntu-libc-malloc, test-ubuntu-no-malloc-usable-size, test-ubuntu-32bit, test-ubuntu-tls, test-ubuntu-tls-no-tls, test-ubuntu-io-threads, test-ubuntu-reclaim-cache, test-valgrind-test, test-valgrind-misc, test-valgrind-no-malloc-usable-size-test, test-valgrind-no-malloc-usable-size-misc, test-sanitizer-address, test-sanitizer-undefined, test-centos7-jemalloc, test-centos7-tls-module, test-centos7-tls-module-no-tls, test-macos-latest, test-macos-latest-sentinel, test-macos-latest-cluster, build-macos, test-freebsd, test-alpine-jemalloc, test-alpine-libc-malloc, reply-schemas-validator]
+    steps:
+      - name: Collect job status
+        run: |
+          FAILED_JOBS=()
+          NEEDS_JSON='${{ toJSON(needs) }}'
+          JOBS=($(echo "$NEEDS_JSON" | jq 'keys' | tr -d '[] ,'))
+          for JOB in ${JOBS[@]}; do
+            JOB_RESULT=$(echo "$NEEDS_JSON" | jq ".[$JOB][\"result\"]" | tr -d '"')
+            if [ $JOB_RESULT = "failure" ]; then
+              FAILED_JOBS+=($JOB)
+            fi
+          done
+          
+          if [[ ${#FAILED_JOBS[@]} -ne 0 ]]; then
+            echo "FAILED_JOBS=${FAILED_JOBS[@]}" >> $GITHUB_ENV
+            echo "STATUS=failure" >> $GITHUB_ENV
+          else
+            echo "STATUS=success" >> $GITHUB_ENV
+          fi
+      - name: Notify about results
+        uses: ravsamhq/notify-slack-action@v2
+        with:
+          status: ${{ env.STATUS }}
+          notify_when: "failure"
+          notification_title: "Daily test run <${{github.server_url}}/${{github.repository}}/actions/runs/${{github.run_id}}|Failure>"
+          message_format: ":fire: Tests failed: ${{ env.FAILED_JOBS }}"
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_NOTIFICATIONS_WEBHOOK_URL }}