Avoid raising when constantizing from paths

[jeffcarbs]

Motivation

#968 added support for generating DSL RBI via a path like bin/tapioca dsl app/models. The way it works is using Static::SymbolLoader.symbols_from_paths to find all constants defined in those paths and then acting as if you called bin/tapioca dsl <those constants>.

When testing this out for the first time, I realized that sometimes symbols_from_paths found constants that weren't actually loaded (or loadable) and would then raise an exception. Two common examples in our codebase:

1. A constant defined inside an eigenclass, for example

class Foo
  class << self
    BAR = nil
  end
end

In this example, Foo::BAR is a constant returned from symbols_from_paths but you can't actually reference it outside the eigenclass.

2. Any constants (e.g. helper modules) defined in test folders. We use packwerk so my first command was something like bin/tapioca dsl packs/xyz which is a folder than contains both app and spec so it found a few constants from tests and blew up trying to load them.

Implementation

When generating DSL for specific constants like bin/tapioca dsl Some::Constant we raise if that constant can't be resolved. This makes sense since you're explicitly asking us to generate DSL for a specific constant.

We previously had the same behavior for constants derived from given paths, however this PR changes that behavior so we'll simply ignore constants that cannot be resolved. This makes sense to me since by doing bin/tapioca dsl some/path you're essentially saying "generate RBI for whatever you can in some/path".

Tests

Added a test for the eigenclass case and confirmed it failed before and passed after this change. I also tested out this branch of tapioca on Gusto's codebase and it worked as expected 👍

[jeffcarbs]

I intentionally removed this warning since we already logic to show an error for bad paths (see #968 (comment) for more details).

[egiurleo]

Thanks @jeffcarbs!