[dev] CI: drop mirrors.yml workflow. (#52613)

Drop mirrors.yml workflow from GitHub actions, passing but trying to update a non-existent production repository. The production repositories project is on hold, and we can restore the workflow if the project gets traction.

.github/workflows/mirrors.yml

@@ -1,84 +0,0 @@
-name: Mirrors
-on:
-  push:
-    branches: ["trunk", "release/**"]
-  workflow_dispatch:
-
-permissions: {}
-
-jobs:
-  build:
-    if: github.repository == 'woocommerce/woocommerce'
-    name: Build WooCommerce zip
-    runs-on: ubuntu-20.04
-    permissions:
-      contents: read
-    steps:
-      - uses: actions/checkout@v3
-
-      - name: Setup WooCommerce Monorepo
-        uses: ./.github/actions/setup-woocommerce-monorepo
-        with:
-          pull-package-deps: '@woocommerce/plugin-woocommerce'
-
-      - name: Build zip
-        working-directory: plugins/woocommerce
-        run: bash bin/build-zip.sh
-
-      - name: Upload the zip file as an artifact
-        uses: actions/upload-artifact@v4
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          name: woocommerce
-          path: plugins/woocommerce/woocommerce.zip
-          retention-days: 7
-
-  mirror:
-    if: github.repository == 'woocommerce/woocommerce'
-    name: Push to Mirror
-    needs: [build]
-    runs-on: ubuntu-20.04
-    permissions:
-      contents: read
-    steps:
-      - name: Create directories
-        run: |
-          mkdir -p monorepo
-
-      - name: Checkout monorepo
-        uses: actions/checkout@v3
-        with:
-          path: monorepo
-
-      - name: Download WooCommerce ZIP
-        uses: actions/download-artifact@v4
-        with:
-          name: woocommerce
-          path: tmp/woocommerce-build
-
-      - name: Extract and replace WooCommerce zip.
-        working-directory: tmp/woocommerce-build
-        run: |
-          mkdir -p woocommerce/woocommerce-production
-          unzip woocommerce.zip -d woocommerce/woocommerce-production
-          mv woocommerce/woocommerce-production/woocommerce/* woocommerce/woocommerce-production
-          rm -rf woocommerce/woocommerce-production/woocommerce
-
-      - name: Copy Composer over to production
-        run: cp monorepo/plugins/woocommerce/composer.json tmp/woocommerce-build/woocommerce/woocommerce-production
-
-      - name: Set up mirror
-        working-directory: tmp/woocommerce-build
-        run: |
-          touch mirrors.txt
-          echo "woocommerce/woocommerce-production" >> mirrors.txt
-
-      - name: Push to mirror
-        uses: Automattic/action-push-to-mirrors@v1
-        with:
-          source-directory: ${{ github.workspace }}/monorepo
-          token: ${{ secrets.API_TOKEN_GITHUB }}
-          username: matticbot
-          working-directory: ${{ github.workspace }}/tmp/woocommerce-build
-        timeout-minutes: 5 # 2021-01-18: Successful runs seem to take about half a minute.