Label External Issues: Update secret, add discussions (#897)

This PR updates the secret in the external issue labeler GHA to use one with permissions to see who is a member of `nv-morpheus`.

It also auto-labels new external discussions with the `Needs Triage` label as well.

Authors:
  - Ben Jarmak (https://github.com/jarmak-nv)

Approvers:
  - Michael Demoret (https://github.com/mdemoret-nv)

URL: #897

.github/workflows/label-external-issues.yml

@@ -20,9 +20,13 @@ on:
     types:
       - opened
 
+  discussion:
+    types:
+      - created
+
 env:
-  GITHUB_TOKEN: ${{ github.token }}
-  # Label ID from an external graphQL query, represents '? - Needs Triage'
+  GITHUB_TOKEN: ${{ secrets.PROJECT_MANAGEMENT_PAT }}
+  # Label ID from an external graphQL query, represents 'Needs Triage'
   LABEL_ID: LA_kwDOFrb0NM7yzEQv
 
 permissions: