Fix Ci for PHP 8.0

The composer.lock doesn't work for PHP 8.0, so rather than use the lock
file, do a composer update.

Author: akrabat

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [8.0, 8.1, 8.2]
+        php: [8.0, 8.1, 8.2, 8.3]
         experimental: [false]
         include:
           - php: 8.2
@@ -26,7 +26,12 @@ jobs:
           php-version: ${{ matrix.php }}
           coverage: xdebug
 
-      - name: Install dependencies with Composer
+      - name: Install dependencies with Composer (PHP 8.0)
+        if: ${{ matrix.php == 8.0 }}
+        run: rm composer.lock && composer update
+
+      - name: Install dependencies with Composer (PHP 8.1+)
+        if: ${{ matrix.php >= 8.1 }}
         uses: ramsey/composer-install@v2
 
       - name: Coding standards