[11.x] Add Prompts textarea fallback for tests and add assertion tests

[lioneaglesolutions]

This PR adds a fallback for the new textarea component in Laravel Prompts, similar to other components. Without this, you can not use expectsQuestion when using the textarea prompt.

Issue

I don't quite understand the underlying fallbackUsing behaviour but I do know that if it's missing, it causes the tests to hang.

Fixes

• Artisan asserts not working with textarea prompts#131

Tests

I'm not sure if the tests are the right way to go about this but it's the only way I could validate the fix in the framework. If you remove the new Textarea::fallbackUsing(...) and run the new tests, they will hang. I also found some other interesting behaviour when writing those tests but require these to be merged first before I can work on a fix.

Additional PR

If this PR is merged, can #51056 please be looked at as well?

[lioneaglesolutions]

I'm not quite sure how to fix the failing tests - I think they're failing because textarea is only available in the latest version of Laravel but the matrix is checking older versions. I'm not quite sure how to fix that.

[lioneaglesolutions]

I've updated the composer.json to bump the prompts version to at least get the tests passing but not sure if this should be left alone...

[jessarcher]

Thanks, @lioneaglesolutions!

I've updated the fallback to use Symfony's multiline setting. It doesn't matter so much for test assertions, but the fallbacks are also used for Windows users without WSL.

[lioneaglesolutions]

Awesome @jessarcher glad I could help. Any thoughts on #51056?