use an EnvironmentTarget helper instead of direct isinstance checks

[tdyas]

A user reported that Pants was generating a warning for the visibility lint rules because the target was running in an experimental_workspace_environment. As it turns out, several parts of the code were checking EnvironmentTarget.val directly to see if it was an instance of LocalEnvironmentTarget. This is an anti-pattern given that we can introduce new environment types.

This PR fixes the issue by using an existing helper method on EnvironmentTarget. The helper method is renamed to can_access_local_system_paths from can_use_system_path_metadata_requests.

[cognifloyd]

Thank you!

[cognifloyd]

Why did you decide not to cherry-pick to 2.23? Wait till after 2.23.0 (so cherry pick for 2.23.1)?

[tdyas]

Why did you decide not to cherry-pick to 2.23? Wait till after 2.23.0 (so cherry pick for 2.23.1)?

Because this PR won't apply cleanly to 2.23.x. I likely need to back port the commit which added the helper in the first place.

[benjyw]

Why cherry-pick at all? Seems fine not to? This isn't really a user-facing bugfix AFAICT?

[tdyas]

Why cherry-pick at all? Seems fine not to? This isn't really a user-facing bugfix AFAICT?

Users may be confused by the warning if using a workspace environment and some linters as @cognifloyd saw. But to your point, I don't expect a lot of people to hit this so probably can avoid fixing for now.

[cognifloyd]

This is a pretty minor cosmetic issue (an extra warning), so a cherry-pick could have been nice if it was an easily backported fix. It's not, however, so the cherry-pick is not worth it.