feat: add pcntl extension to PHPUnit test workflow

Signed-off-by: Felipe Sayão Lobato Abreu <github@mentordosnerds.com>

Author: coisa

.github/workflows/tests.yml

@@ -50,7 +50,7 @@ jobs:
               uses: php-actions/composer@v6
               with:
                 php_version: ${{ matrix.php-version }}
-                php_extensions: pcov
+                php_extensions: pcov,pcntl
                 command: 'dev-tools'
                 args: 'tests -- --coverage=public/coverage'