Warn and reraise LoadError instead of raising custom error

[bdewater-thatch]

When upgrading to image_processing 2.0 and removing the image_magick gem (which we don't use) we ran into errors with Tapioca requiring all gems to compile RBI files. The quick fix was to add back image_magick, but the IMO proper fix is re-raising the original LoadError from Bundler which is handled by Tapioca. With these changes Tapioca can compile RBI for image_processing, just without the ImageProcessing::MiniMagick module being present.

The warn + reraise pattern is for example how Rails handles bcrypt: https://github.com/rails/rails/blob/fa8f0812160665bff083a089d2bb2fc1817ea03e/activemodel/lib/active_model/secure_password.rb#L129-L134

[janko]

Yes, it seems correct to raise LoadError here. Would Tapioca still rescue it if we raised LoadError with the custom message equal to current warning message? I feel like that way we ensure the friendly error won't be overlooked. For example, Active Storage raises a custom LoadError when image_processing gem is missing.

[bdewater-thatch]

Yes, Tapioca doesn't care about the message. I've amended the PR.

[janko]

Thanks!