tests: mark tests that fail when using chg as #require no-chg

Authored by spectral.

Description

tests: mark tests that fail when using chg as #require no-chg

As far as I can tell, most of these failures are due to using $HGPORT, which it
seems chg might be using itself? I don't know enough to debug these failures to
fix them properly.

Differential Revision: https://phab.mercurial-scm.org/D3562