minor: Update dev tools

[kubawerlos]

Updating all dev tools and:

• removing workaround added in DX: run static code analysis on PHP 8.0 #5775 (humbug/php-scoper alias).
• PHP can be restricted as both SCA and PHAR's build jobs are running on PHP 8.1
• made by simply running:

  composer remove --dev humbug/php-scoper --no-update
  composer update
  composer show -ND | xargs composer rb --dev -W

  (rb stands for require-better)

[coveralls]

Coverage remained the same at 92.913% when pulling bc1b07d on werlos:update_dev_tools into 531eaeb on FriendsOfPHP:master.