[stable-2.7] ansible-test - add constraint for virtualenv (#67289)

* ansible-test - add constraint for virtualenv

* Limit virtualenv only on macOS.

Co-authored-by: Matt Clay <matt@mystile.com>.
(cherry picked from commit 8f296a6533)

Co-authored-by: Sam Doran <sdoran@redhat.com>

changelogs/fragments/ansible-test-constraints-virtualenv.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ansible-test - Use ``virtualenv`` versions before 20 on provisioned macOS instances to remain compatible with an older pip install.

test/runner/setup/remote.sh

@@ -43,7 +43,7 @@ elif [ "${platform}" = "rhel" ]; then
 fi
 
 if [ "${platform}" = "freebsd" ] || [ "${platform}" = "osx" ]; then
-    pip install virtualenv
+    pip install 'virtualenv<20'
 
     # Tests assume loopback addresses other than 127.0.0.1 will work.
     # Add aliases for loopback addresses used by tests.