Remove GitHub workflow

.github/workflows/ci.yaml

@@ -1,60 +0,0 @@
----
-name: CI
-
-on: [push, pull_request]
-
-jobs:
-  php-cs-fixer:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2
-        with:
-          ref: ${{ github.head_ref }}
-
-      - name: Run php-cs-fixer
-        uses: docker://oskarstark/php-cs-fixer-ga
-
-      - name: Commit changes
-        uses: stefanzweifel/git-auto-commit-action@v4
-        with:
-          commit_message: Apply php-cs-fixer changes
-
-  phpunit:
-    name: PHPUnit (PHP ${{ matrix.php-versions }})
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-      matrix:
-        php-versions: ['8.1']
-
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v2
-
-      - name: Composer install
-        uses: php-actions/composer@v5
-
-      - name: Run PHPUnit tests
-        run: composer test
-
-  phpstan:
-    name: phpstan (PHP ${{ matrix.php-versions }})
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-      matrix:
-        php-versions: ['8.1']
-
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v2
-
-      - name: Composer install
-        uses: php-actions/composer@v5
-
-      - name: Run phpstan
-        run: composer phpstan