run-tests: stop ignoring venv-installed packages
This will allow test dependencies to be installed within a venv, instead of
tampering with sys/user sites. One thing to note here is that the `VIRTUAL_ENV`
path takes precedence over system-site, unlike when run directly with an
activated `venv`. For example, `sys.path` as viewed from a feature test in
`hghave.py`, when running `hghave vcr` directly with an activated `venv`:
sys.path: [
'/home/jenkins/hg-committed/tests',
'/usr/lib/python38.zip',
'/usr/lib/python3.8',
'/usr/lib/python3.8/lib-dynload',
'/home/jenkins/test_venv/lib/python3.8/site-packages'
]
vs `sys.path` from the same feature test, when run by `run-tests.py` with this
change:
sys.path: [
'/home/jenkins/hg-committed/tests',
'/home/jenkins/hg-committed',
'/home/jenkins/hg-committed/tests',
'/home/jenkins/test_venv/lib/python3.8/site-packages',
'/usr/lib/python38.zip',
'/usr/lib/python3.8',
'/usr/lib/python3.8/lib-dynload',
'/home/jenkins/.local/lib/python3.8/site-packages',
'/usr/local/lib/python3.8/dist-packages',
'/usr/lib/python3/dist-packages'
]
ERROR: FIXME: This is a known failure of filelog.size for data starting with \1\n
OK.