chore: only notify about CI failure on main if required job fails (#16114)

This should be the last PR to get this working

Looks like the `nightly-gauntlet` is working as expected, and this is a
clone of that.

---------

Signed-off-by: Danny Kopping <danny@coder.com>

.github/workflows/ci.yaml

@@ -1252,8 +1252,10 @@ jobs:
           make sqlc-vet
 
   notify-slack-on-failure:
+    needs:
+      - required
     runs-on: ubuntu-latest
-    if: always() && failure() && github.ref == 'refs/heads/main'
+    if: failure() && github.ref == 'refs/heads/main'
 
     steps:
       - name: Send Slack notification
@@ -1276,10 +1278,6 @@ jobs:
                     "type": "mrkdwn",
                     "text": "*Workflow:*\n${{ github.workflow }}"
                   },
-                  {
-                    "type": "mrkdwn",
-                    "text": "*Failed Job:*\n${{ github.job }}"
-                  },
                   {
                     "type": "mrkdwn",
                     "text": "*Committer:*\n${{ github.actor }}"

.github/workflows/nightly-gauntlet.yaml

@@ -101,10 +101,6 @@ jobs:
                     "type": "mrkdwn",
                     "text": "*Workflow:*\n${{ github.workflow }}"
                   },
-                  {
-                    "type": "mrkdwn",
-                    "text": "*Failed Job:*\n${{ github.job }}"
-                  },
                   {
                     "type": "mrkdwn",
                     "text": "*Committer:*\n${{ github.actor }}"