update GH actions

Author: mmoll

.github/workflows/ci.yml

@@ -13,14 +13,14 @@ jobs:
       - name: install dependencies
         run: sudo apt update -qq && sudo apt -y install libxml2-utils
       - name: Check out repository code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Install PHP
-        uses: shivammathur/setup-php@v2
+        uses: shivammathur/setup-php@v3
         with:
           php-version: '7.4'
           coverage: 'none'
       - name: Cache dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: '~/.cache/composer'
           key: "cache-composer-${{ hashFiles('composer.json') }}"