ci: assigner: do not check permission/manifest on branches

Workaround GH running workflows from main on release branches.
The assignment script fails and does wrong assignments based on wrong
versions of the maintainer file and manifest.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

.github/workflows/assigner.yml

@@ -38,7 +38,7 @@ jobs:
 
     - name: Fetch west.yml/Maintainer.yml from pull request
       if: >
-        github.event_name == 'pull_request_target'
+        github.event_name == 'pull_request_target' && github.base_ref == 'main'
       run: |
         git fetch origin pull/${{ github.event.pull_request.number }}/merge
         git show FETCH_HEAD:west.yml > pr_west.yml
@@ -61,7 +61,11 @@ jobs:
         FLAGS+=" -r ${{ github.event.repository.name }}"
         FLAGS+=" -M MAINTAINERS.yml"
         if [ "${{ github.event_name }}" = "pull_request_target" ]; then
-          FLAGS+=" -P ${{ github.event.pull_request.number }} --updated-manifest pr_west.yml --updated-maintainer-file pr_MAINTAINERS.yml"
+          if [ "${{ github.base_ref }}" != "main" ]; then
+            FLAGS+=" -P ${{ github.event.pull_request.number }} --updated-manifest pr_west.yml --updated-maintainer-file pr_MAINTAINERS.yml"
+          else
+            FLAGS+=" -P ${{ github.event.pull_request.number }}
+          fi
         elif [ "${{ github.event_name }}" = "issues" ]; then
           FLAGS+=" -I ${{ github.event.issue.number }}"
         elif [ "${{ github.event_name }}" = "schedule" ]; then
@@ -74,7 +78,7 @@ jobs:
 
     - name: Check maintainer file changes
       if: >
-        github.event_name == 'pull_request_target'
+        github.event_name == 'pull_request_target' && github.base_ref == 'main'
       env:
         GITHUB_TOKEN: ${{ secrets.ZB_PR_ASSIGNER_GITHUB_TOKEN }}
       run: |