At some point #2004 regressed, either in general or for LSPs specifically.

Option values should only be evaluated when they are used; i.e. when the feature using them is enabled. For package options, this means the package itself should only be evaluated when that package is being installed in the nixvim config.

E.g., #3780 and https://discourse.nixos.org/t/error-atopile-cannot-be-found-in-pkgs/70461 show that the atopile package options are being evaluated strictly, even when that specific LSP isn't enabled.

We should be able to enforce laziness by having a test that evaluates nixvim with pkgs = {}. Maybe we will also need variants of that test that enable portions of nixvim that shouldn't install any packages?