v2026.02.16.00

ensure third-party directory exists before canonicalizing (#97)

Summary:
When first setting up reindeer in a buck project where you haven't already created the `third-party` dir, the `dunce::canonicalize` call always fails with the typical `No such file or directory (os error 2)` error. This also means the "on-demand creation" logic is never actually hit.

This change moves up this "on-demand creation" logic to be run *before* we attempt to canonicalize the path.

I figured `path` is probably the right module to put this in, let me know if not.

Pull Request resolved: https://github.com/facebookincubator/reindeer/pull/97

Reviewed By: diliop

Differential Revision: D93331550

Pulled By: dtolnay

fbshipit-source-id: afd892b573e200d6cfb287981e99135f306cc5d9