Remove frontend auto-update workflow (#6539)

Remove the automated frontend update workflow and version tracking file
as the frontend repository no longer builds supervisor-specific assets.
Frontend updates will now follow a different distribution mechanism.

Related to home-assistant/frontend#29132

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

.github/workflows/update_frontend.yml

@@ -1,82 +0,0 @@
-name: Update frontend
-
-on:
-  schedule: # once a day
-    - cron: "0 0 * * *"
-  workflow_dispatch:
-
-jobs:
-  check-version:
-    runs-on: ubuntu-latest
-    outputs:
-      skip: ${{ steps.check_version.outputs.skip || steps.check_existing_pr.outputs.skip }}
-      current_version: ${{ steps.check_version.outputs.current_version }}
-      latest_version: ${{ steps.latest_frontend_version.outputs.latest_tag }}
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
-      - name: Get latest frontend release
-        id: latest_frontend_version
-        uses: abatilo/release-info-action@32cb932219f1cee3fc4f4a298fd65ead5d35b661 # v1.3.3
-        with:
-          owner: home-assistant
-          repo: frontend
-      - name: Check if version is up to date
-        id: check_version
-        run: |
-          current_version="$(cat .ha-frontend-version)"
-          latest_version="${{ steps.latest_frontend_version.outputs.latest_tag }}"
-          echo "current_version=${current_version}" >> $GITHUB_OUTPUT
-          echo "LATEST_VERSION=${latest_version}" >> $GITHUB_ENV
-          if [[ ! "$current_version" < "$latest_version" ]]; then
-            echo "Frontend version is up to date"
-            echo "skip=true" >> $GITHUB_OUTPUT
-          fi
-      - name: Check if there is no open PR with this version
-        if: steps.check_version.outputs.skip != 'true'
-        id: check_existing_pr
-        env:
-          GH_TOKEN: ${{ github.token }}
-        run: |
-          PR=$(gh pr list --state open --base main --json title --search "Update frontend to version $LATEST_VERSION")
-          if [[ "$PR" != "[]" ]]; then
-            echo "Skipping - There is already a PR open for version $LATEST_VERSION"
-            echo "skip=true" >> $GITHUB_OUTPUT
-          fi
-  create-pr:
-    runs-on: ubuntu-latest
-    needs: check-version
-    if: needs.check-version.outputs.skip != 'true'
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
-      - name: Clear www folder
-        run: |
-          rm -rf supervisor/api/panel/*
-      - name: Update version file
-        run: |
-          echo "${{ needs.check-version.outputs.latest_version }}" > .ha-frontend-version
-      - name: Download release assets
-        uses: robinraju/release-downloader@daf26c55d821e836577a15f77d86ddc078948b05 # v1.12
-        with:
-          repository: 'home-assistant/frontend'
-          tag: ${{ needs.check-version.outputs.latest_version }}
-          fileName: home_assistant_frontend_supervisor-${{ needs.check-version.outputs.latest_version }}.tar.gz
-          extract: true
-          out-file-path: supervisor/api/panel/
-      - name: Remove release assets archive
-        run: |
-          rm -f supervisor/api/panel/home_assistant_frontend_supervisor-*.tar.gz
-      - name: Create PR
-        uses: peter-evans/create-pull-request@c0f553fe549906ede9cf27b5156039d195d2ece0 # v8.1.0
-        with:
-          commit-message: "Update frontend to version ${{ needs.check-version.outputs.latest_version }}"
-          branch: autoupdate-frontend
-          base: main
-          draft: true
-          sign-commits: true
-          title: "Update frontend to version ${{ needs.check-version.outputs.latest_version }}"
-          body: >
-            Update frontend from ${{ needs.check-version.outputs.current_version }} to
-            [${{ needs.check-version.outputs.latest_version }}](https://github.com/home-assistant/frontend/releases/tag/${{ needs.check-version.outputs.latest_version }})
-