ci: drop slack webhook step and skip last-attempt sleep

Existing org-level Slack notifications already fire on job failure for
this repo, so a dedicated SLACK_RELEASE_WEBHOOK_URL step was redundant.
Removing it eliminates the unprovisioned secret and the silent no-op
fallback. The job still fails non-zero on exhausted retries (no
continue-on-error), which is what the existing notifier hooks into.

Also guard the retry-loop sleep with `attempt -lt 3` so the loop no
longer sleeps 90s after the final failed attempt before exit 1.

Ticket: VL-6353
Session-Id: 171773d2-746b-4f79-8b23-5ad8c11f2e5e
Task-Id: d6793c61-de39-41c3-80f1-5352025fb58c

Author: roshan-bitgo

.github/workflows/npmjs-release.yml

@@ -307,7 +307,8 @@ jobs:
 
       # NPM publish has already happened by this point, so a failure here
       # requires manual remediation (see VL-5474). Retry transient failures,
-      # then surface as a job failure — no continue-on-error.
+      # then surface as a job failure — no continue-on-error. Existing
+      # org-level Slack notifications fire on the resulting job failure.
       - name: Create GitHub release
         if: inputs.dry-run == false && steps.version-bump-summary.outcome == 'success'
         id: create-github-release
@@ -322,33 +323,15 @@ jobs:
               echo "GitHub release created on attempt $attempt"
               exit 0
             fi
-            delay=$((attempt * 30))
-            echo "Attempt $attempt failed. Retrying in ${delay}s..."
-            sleep "$delay"
+            if [ "$attempt" -lt 3 ]; then
+              delay=$((attempt * 30))
+              echo "Attempt $attempt failed. Retrying in ${delay}s..."
+              sleep "$delay"
+            fi
           done
-          echo "::error::All retry attempts exhausted creating GitHub release v${{ steps.extract-version.outputs.new-version }}."
+          echo "::error::All retry attempts exhausted creating GitHub release v${{ steps.extract-version.outputs.new-version }}. NPM publish succeeded; manual GitHub release required."
           exit 1
 
-      - name: Notify on GitHub release failure
-        if: ${{ always() && steps.create-github-release.outcome == 'failure' }}
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_RELEASE_WEBHOOK_URL }}
-          VERSION: ${{ steps.extract-version.outputs.new-version }}
-          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
-        run: |
-          echo "::error::GitHub release creation failed after 3 attempts for v${VERSION}. NPM publish succeeded; create the GitHub release manually. Run: ${RUN_URL}"
-          if [ -z "$SLACK_WEBHOOK_URL" ]; then
-            echo "::warning::SLACK_RELEASE_WEBHOOK_URL is not configured; skipping Slack notification."
-            exit 0
-          fi
-          payload=$(jq -nc \
-            --arg text ":rotating_light: BitGoJS GitHub release creation failed for v${VERSION} after 3 retries. NPM publish already succeeded — manual GitHub release required. Run: ${RUN_URL}" \
-            '{text: $text}')
-          curl -sS -X POST -H 'Content-Type: application/json' \
-            --data "$payload" \
-            --retry 3 --retry-delay 5 --max-time 30 \
-            "$SLACK_WEBHOOK_URL" || echo "::warning::Slack notification POST failed."
-
   get-express-release-context:
     name: Get Express release context
     if: ${{ always() && inputs.dry-run == false && needs.release-bitgojs.result == 'success' }}