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
Hello, Foobar
[b'Hello, Fo, =;:<o', b'Hello, Bar']