ci: remove releases-json workflow

This is now directly handled by our actions-toolkit. We keep
`.github/releases.json` file for now but will be removed on
next v0.11 release.

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/releases-json.yml

@@ -1,56 +0,0 @@
-name: releases-json
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
-on:
-  workflow_dispatch:
-  release:
-    types:
-      - released
-  pull_request:
-    paths-ignore:
-      - '.github/releases.json'
-
-jobs:
-  generate:
-    uses: crazy-max/.github/.github/workflows/releases-json.yml@2a596c917a8ad3e6203ae99b777148525a2e00d5
-    with:
-      repository: docker/buildx
-      artifact_name: releases-json
-      filename: releases.json
-    secrets: inherit
-
-  open-pr:
-    runs-on: ubuntu-22.04
-    if: github.event_name != 'pull_request'
-    needs:
-      - generate
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v3
-      -
-        name: Download
-        uses: actions/download-artifact@v3
-        with:
-          name: releases-json
-          path: .github
-      -
-        name: Commit changes
-        run: |
-          git add -A .
-      -
-        name: Create PR
-        uses: peter-evans/create-pull-request@2b011faafdcbc9ceb11414d64d0573f37c774b04
-        with:
-          base: master
-          branch: bot/releases-json
-          commit-message: "github: update .github/releases.json"
-          signoff: true
-          delete-branch: true
-          title: "Update `.github/releases.json`"
-          body: |
-            Update `.github/releases.json` to keep in sync with GitHub Releases.
-          draft: false