Ignore invalid paths

[ahmedash95]

Why?

While removing a directory that is parked in Valet. I encountered an error originating from Herd's Valet, though the issue lies with Valet itself. And from a user's perspective, I believe Valet should remain operational even if one of the paths is invalid

Suggestion

Introducing a command such as valet check would be beneficial. It could report on Valet's status, confirming if all paths are correct or if any path is invalid.

[drbyte]

I agree with this code change.

For cleanup, perhaps the valet paths command could offer to cleanup any invalid paths when it displays the ones it has registered. I'd support a PR or discussion for implementing that.

[driesvints]

Thanks!