chore: call the release notes assistant when opening a new pull request (#964)

When a new pull request is opened and has no labels, the release notes
assistant will not be called and it will look like the event was
missed.

Most of the time the label will be set when the pull request is open
and that will fire two runs. However, the release notes assistant is
idempotent and that will just make one extra run in the CI that is a
noop.

<!--start release-notes-assistant-->
<!--URL:https://code.forgejo.org/forgejo/runner-->
- other
  - [PR](https://code.forgejo.org/forgejo/runner/pulls/964): <!--number 964 --><!--line 0 --><!--description Y2hvcmU6IGNhbGwgdGhlIHJlbGVhc2Ugbm90ZXMgYXNzaXN0YW50IHdoZW4gb3BlbmluZyBhIG5ldyBwdWxsIHJlcXVlc3Q=-->chore: call the release notes assistant when opening a new pull request<!--description-->
<!--end release-notes-assistant-->

Reviewed-on: https://code.forgejo.org/forgejo/runner/pulls/964
Reviewed-by: Gusted <gusted@noreply.code.forgejo.org>
Co-authored-by: Earl Warren <contact@earl-warren.org>
Co-committed-by: Earl Warren <contact@earl-warren.org>

.forgejo/workflows/release-notes-assistant.yml

@@ -6,6 +6,7 @@ name: issue-labels
 on:
   pull_request_target:
     types:
+      - opened
       - edited
       - synchronize
       - labeled
@@ -14,14 +15,6 @@ env:
   RNA_VERSION: v1.4.0 # renovate: datasource=forgejo-releases depName=forgejo/release-notes-assistant registryUrl=https://code.forgejo.org
 
 jobs:
-  debug:
-    runs-on: docker
-    steps:
-      - name: event
-        run: |
-          cat <<'EOF'
-          ${{ toJSON(forge) }}
-          EOF
   release-notes:
     if: vars.ROLE == 'forgejo-coding' && !contains(forge.event.pull_request.labels.*.name, 'Kind/DependencyUpdate')
     runs-on: docker