Add GH release creation to scheduled security builds, update deprecated workflow components

- scheduled-build.yml: Create GitHub release after each weekly security
  rebuild with date-stamped tag (e.g. noble-1.0.2-security.20260227)
- scheduled-build.yml: Add date-stamped Docker image tags alongside
  existing version and codename tags
- scheduled-build.yml: Bump permissions to contents:write for release
  creation
- scheduled-build.yml: Exclude security-tagged releases from base
  version lookup to prevent nested tags
- main.yml: Update docker/build-push-action from v5 to v6
- scheduled-build.yml: Update docker/build-push-action from v5 to v6
- stale.yml: Remove deprecated repo-token parameter

Co-authored-by: samip5 <1703002+samip5@users.noreply.github.com>

.github/workflows/main.yml

@@ -2,18 +2,12 @@ name: Release
 
 on:
     workflow_dispatch:
-    push:
-        tags:
-            - 'noble-*'
-            - 'jammy-*'
-
-permissions:
-    contents: write
-    packages: write
-
+    release:
+     types: [published]
 jobs:
     build:
         runs-on: ubuntu-latest
+        if: "!contains(github.event.head_commit.message, '[ci-skip]')"
         steps:
           - name: Checkout
             uses: actions/checkout@v4
@@ -90,13 +84,3 @@ jobs:
               push: ${{ steps.prep.outputs.push }}
               tags: ${{ steps.prep.outputs.tags }}
               build-args: BASE_IMAGE=${{ steps.prep.outputs.base_image }}
-
-          - name: Create GitHub Release
-            if: startsWith(github.ref, 'refs/tags/')
-            run: |
-              gh release create "${{ github.ref_name }}" \
-                --repo "${{ github.repository }}" \
-                --title "${{ github.ref_name }}" \
-                --generate-notes
-            env:
-              GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}