pyoxidized: disable part of `test-install.t` related to pip and virtualenv

This part are testing manual installation of Mercurial, this is not relevant
for the pyoxidizer variant.

Differential Revision: https://phab.mercurial-scm.org/D11296

tests/test-install.t

@@ -184,7 +184,7 On Python 2, we use the 3rd party virtua
   $ cd $TESTTMP
   $ unset PYTHONPATH
 
-#if py3 ensurepip network-io
+#if py3 ensurepip network-io no-pyoxidizer
   $ "$PYTHON" -m venv installenv >> pip.log
 
 Hack: Debian does something a bit different in ensurepip.bootstrap. This makes
@@ -224,7 +224,7 since it's bin on most platforms but Scr
   no problems detected
 #endif
 
-#if virtualenv no-py3 network-io
+#if virtualenv no-py3 network-io no-pyoxidizer
 
 Note: --no-site-packages is the default for all versions enabled by hghave