Snyk monitor workflow change (#1549)

# What this PR does
Replaces `snyk test` with `snyk monitor` so results get pushed to out
Snyk platform and the [Snyk
Dashboards](https://ops.grafana-ops.net/d/H0w7l5NVk/snyk-overview?orgId=1)
gets updated.

## Which issue(s) this PR fixes

## Checklist

- [ ] Tests updated
- [ ] Documentation added
- [ ] `CHANGELOG.md` updated

.github/workflows/snyk.yml

@@ -34,6 +34,6 @@ jobs:
         run: yarn install --frozen-lockfile --prefer-offline --network-timeout 500000
       - name: Run Snyk
         continue-on-error: true
-        run: snyk test --all-projects --severity-threshold=high
+        run: snyk monitor --all-projects --severity-threshold=high
         env:
           SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}