[Lint] Lint should not depend on compilation

[ZacSweers]

It runs on ASTs, so it can run in parallel to compilation.

As a potential followup, we can maybe look at making lint optionally run as an implicit concurrent action of building a src target

[ZacSweers]

It looks like this is partially done via removing --classpath in #742, but is there anything else needed for regular genrule ordering? Per the internal ticket this seemed to not be done yet, but unsure where else to look

[kageiit]

The issue is that buck puts the output of the target itself as part of the classpath which means it is still building the target when we dont want it to. We need to make a change to buck to allow a classpath_without_self kind of macro option to get it to do what we want

[ZacSweers]

Is there an upstream issue we can link?

[kageiit]

Dont think we made one. @raviagarwal7 was going to look into it at some point iirc