R1:9a15129b402f

Remove 750ms timeout on owners path validation

Summary:
Ref T13164. See PHI748. Path validation has a 750ms timeout which blames to rP5038ab850c, in 2011.

Production path validation is sometimes taking more than 750ms, particularly on the initial page load where we may validate many paths simultaneously.

I have no idea why we have this timeout, and it isn't consistent with how we perform other AJAX requests. Just remove it.

Test Plan:
- Reproduced issue in production, saw all validation calls failing…