ci: remove the workflow that deletes the untagged images on ghcr.io

- a release pushes its platform images and attestations untagged behind its tagged index, one run would delete them and break every published version

.github/workflows/cleanup-ghcr-untagged.yml

@@ -1,22 +0,0 @@
-name: Cleanup Untagged GHCR Images
-
-on:
-  workflow_dispatch:
-
-permissions:
-  packages: write
-
-jobs:
-  cleanup-all-packages:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        package: ['coolify', 'coolify-helper']
-    steps:
-      - name: Delete untagged ${{ matrix.package }} images
-        uses: actions/delete-package-versions@v5
-        with:
-          package-name: ${{ matrix.package }}
-          package-type: 'container'
-          min-versions-to-keep: 0
-          delete-only-untagged-versions: 'true'