Add the workflow failure notification workflow. (#60)

Author: cjyar

.github/workflows/notify.yaml

@@ -0,0 +1,40 @@
+# DO NOT EDIT THIS FILE.
+# Instead, edit the jsonpatch file (actually YAML) in .github/notify-patch.yaml
+# For docs, see github-actions in the IronCoreLabs/depot repo.
+
+name: Notify
+'on':
+  workflow_run:
+    workflows:
+    - Bump Version
+    - Deploy
+    - Docker
+    - Rebuild all container images
+    - Rust CI
+    - Rust Daily
+    - Scala CI
+    - Scala Daily
+    - TypeScript CI
+    - Update Workflows
+    types:
+    - completed
+    branches:
+    - main
+jobs:
+  on-failure:
+    runs-on: ubuntu-20.04
+    if: ${{ github.event.workflow_run.conclusion != 'success' }}
+    steps:
+    - name: Debug
+      run: cat ${{ github.event_path }}
+    - name: Post to Slack on failure
+      run: "set -x\necho 'Failed a run of <${{ github.event.workflow_run.html_url\
+        \ }}|${{ github.event.workflow_run.name }}> in ${{ github.event.repository.name\
+        \ }}.' > text.txt\necho \"GitHub Workflow Bot\" > username.txt\necho \":bomb:\"\
+        \ > icon_emoji.txt\n# echo \"https://i.chzbgr.com/full/8209966592/h2FE3826C/how-awesome-are-you\"\
+        \ > icon_url.txt\necho \"#build-failures\" > channel.txt\necho '{}' | \\\n\
+        jq --rawfile text text.txt \\\n  --rawfile username username.txt \\\n  --rawfile\
+        \ icon_emoji icon_emoji.txt \\\n  --rawfile channel channel.txt \\\n  '. +\
+        \ {\"text\": $text, \"username\": $username, \"icon_emoji\": $icon_emoji,\
+        \ \"channel\": $channel}' | \\\ncurl -Ssf -d @- -H \"Content-type: application/json\"\
+        \ '${{ secrets.SLACK_BUILD_FAILURE_WEBHOOK }}'\n"