Remove SCOUT_DRIVER=null addition to .env from orchid:install command

[graker]

The addition used to help with setting up Orchid in earlier Laravel versions where scout driver was set to algolia by default. It could lead to errors since algolia was likely not installed.

In current scout.php config https://github.com/laravel/scout/blob/10.x/config/scout.php it is set to collection which is an internal driver so we can remove setting SCOUT_DRIVER=null to .env and let users rely on what they have in scout.php by default.

The PR does that. It removes the call adding the entry to .env, and it removes the setValueEnv() method too as it is private and isn't used anywhere else in InstallCommand class.

[tabuna]

I think this is a good and correct decision, and I’m glad we no longer need this workaround.
However, the default driver was switched to collection only starting from version v10.19.1.

To avoid potential conflicts, it would be great to explicitly reflect this in composer.json by adding:

"conflict": {
    "laravel/scout": "<10.19.1"
}

It also makes sense to completely remove this dependency for the 9.x branch.

[graker]

To avoid potential conflicts, it would be great to explicitly reflect this in composer.json by adding

Done. Though I'm not so sure if it's needed: if someone installs Orchid and doesn't have laravel/scout already, they will probably get the latest version (unless other restrictions of course). And if they do have scout, they likely have it already configured and not updating .env won't break anything for them. At the same time, the only reason to require 10.19.1 is that scout driver won't be set to null instead of algolia and other than that the package should be perfectly functional with scout 9 or 10. But maybe I just don't see the full picture.

It also makes sense to completely remove this dependency for the 9.x branch.

I don't think I understand, what to remove for the 9.x branch? 9.x of scout?