infra: actions: fix docker changes detector so it doesnt always build on force pushes

.gitea/workflows/gentoo-utils.yml

@@ -16,13 +16,13 @@ jobs:
         id: image-changes
         # build image only if 1. changes are detected or 2. an image for the working branch doesnt exist
         run: |
-          git --no-pager log --oneline
           echo "BEFORE = ${{ gitea.event.before }}"
           branch_name="${GITHUB_HEAD_REF:-${GITHUB_REF#refs/heads/}}"
           default_branch_name="${{ gitea.event.repository.default_branch }}"
           image_tag=latest
           comparison_hash="${{ gitea.event.before }}"
 
+          git --no-pager reflog -n $(git rev-list --count HEAD ^origin/$default_branch_name)
           if [[ "$branch_name" != "${{ gitea.event.repository.default_branch }}" ]]; then
             image_tag=$branch_name
           fi