fix(ci): remove pull_request trigger from release-drafter workflow

The release-drafter was triggering on every PR open/sync, which caused
a 'Validation Failed: invalid target_commitish' error because
refs/pull/*/merge is not a valid target for updating a release draft.

The autolabeler feature is not configured (commented out), so the
pull_request trigger served no purpose. Removing it so the workflow
only runs on pushes to main, which is the intended behavior.

Fixes: 'Validation Failed: {"resource":"Release","code":"invalid","field":"target_commitish"}'

Author: Ritchie

.github/workflows/release-drafter.yml

@@ -5,13 +5,9 @@ on:
     # branches to consider in the event; optional, defaults to all
     branches:
       - main
-  # pull_request event is required only for autolabeler
-  pull_request:
-    # Only following types are handled by the action, but one can default to all as well
-    types: [opened, reopened, synchronize]
-  # pull_request_target event is required for autolabeler to support PRs from forks
-  # pull_request_target:
-  #   types: [opened, reopened, synchronize]
+  # pull_request trigger removed: autolabeler is not configured,
+  # and running on PRs causes "invalid target_commitish" errors
+  # because refs/pull/*/merge cannot be used as a release target.
 
 permissions:
   contents: read
@@ -26,12 +22,7 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-latest
     steps:
-      # (Optional) GitHub Enterprise requires GHE_HOST variable set
-      #- name: Set GHE_HOST
-      #  run: |
-      #    echo "GHE_HOST=${GITHUB_SERVER_URL##https:\/\/}" >> $GITHUB_ENV
-
-      # Drafts your next Release notes as Pull Requests are merged into "master"
+      # Drafts your next Release notes as Pull Requests are merged into "main"
       - uses: release-drafter/release-drafter@v7
         # (Optional) specify config name to use, relative to .github/. Default: release-drafter.yml
         # with: