tests: always access the mercurial repo through `helpers-testrepo.sh`...
tests: always access the mercurial repo through `helpers-testrepo.sh`
In some contexts the mercurial repo needs to be accessed through system hg.
That's what `helpers-testrepo.sh` enforces, but some tests incorrectly
use the mercurial repo without going through that script.
This patch fixes those tests.