array in .env file

In App.php there is an array variable:
    public $toolbarCollectors = [
        'CodeIgniter\Debug\Toolbar\Collectors\Timers',
        'CodeIgniter\Debug\Toolbar\Collectors\Database',
        'CodeIgniter\Debug\Toolbar\Collectors\Logs',
        'CodeIgniter\Debug\Toolbar\Collectors\Views',
//        'CodeIgniter\Debug\Toolbar\Collectors\Cache',
        'CodeIgniter\Debug\Toolbar\Collectors\Files',
        'CodeIgniter\Debug\Toolbar\Collectors\Routes',
        'CodeIgniter\Debug\Toolbar\Collectors\Events',
    ];

Is it possible to define an array variable in .env file?
For example:
app.css_files = [
     'bootstrap.css',
     'fontawesome.css',
     'stylesheet.css'
]
or
app.css_files = ['bootstrap.css', 'fontawesome.css', 'stylesheet.css']