Improve composer.json

[williamdes]

I removed the "archive" part that I had added, it does not work.

Using @php ensures that the composer commands can be run with different php versions, else it would not work.

php8.x /bin/composer run phpunit

[coveralls]

coverage: 99.872%. remained the same
when pulling 3db1552 on williamdes:patch-1
into 753e964 on slimphp:master.

[akrabat]

Thanks.