Fix testing out of the box

[gp-lnuff]

TestCase.php is using providers from other filament packages, but only filament/forms is installed through composer.json. This breaks testing out of the box since the default tests can't load the service providers for those packages. The most straightforward solution is to remove the providers from the getPackageProviders() method. If for some reason those providers were actually required, an alternative could be to include the packages that include them in composer.json under require-dev

[CodeWithDennis]

There aren’t any tests yet, but I plan to add them to the package at some point (when I have time) — or if someone else contributes a PR. For now, I’m fine with accepting the current PR.