Add copilot-setup-steps.yml to configure GitHub Copilot environment

.github/workflows/copilot-setup-steps.yml

@@ -0,0 +1,46 @@
+name: "Copilot Setup Steps"
+
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+  pull_request:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+
+jobs:
+  copilot-setup-steps:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Check existence of composer.json file
+        id: check_composer_file
+        uses: andstor/file-existence-action@v3
+        with:
+          files: "composer.json"
+
+      - name: Set up PHP environment
+        if: steps.check_composer_file.outputs.files_exists == 'true'
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 'latest'
+          ini-values: zend.assertions=1, error_reporting=-1, display_errors=On
+          coverage: 'none'
+          tools: composer,cs2pr
+        env:
+          COMPOSER_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Install Composer dependencies & cache dependencies
+        if: steps.check_composer_file.outputs.files_exists == 'true'
+        uses: ramsey/composer-install@v3
+        env:
+          COMPOSER_ROOT_VERSION: dev-${{ github.event.repository.default_branch }}
+        with:
+          # Bust the cache at least once a month - output format: YYYY-MM.
+          custom-cache-suffix: $(date -u "+%Y-%m")

.github/workflows/sync-workflows.yml

@@ -22,6 +22,7 @@ jobs:
           FILE_PATTERNS: |
             ^.actrc
             ^.editorconfig
+            ^.github/workflows/copilot-setup-steps.yml
             ^.github/workflows/regenerate-readme.yml
             ^AGENTS.md
           TARGET_REPOS: |