Drop GALAXY_VIRTUAL_ENV env hack

GALAXY_VIRTUAL_ENV is injected through job_wrapper.galaxy_virtual_env,
which does `os.environ.get(VIRTUAL_ENV, None)`, so this didn't work.
The previous commit addresses that.

lib/galaxy/jobs/runners/kubernetes.py

@@ -263,14 +263,6 @@ def __get_k8s_containers(self, ajs):
         k8s_container = {
             "name": self.__get_k8s_container_name(ajs.job_wrapper),
             "image": self._find_container(ajs.job_wrapper).container_id,
-            "env": [{
-                "name": "GALAXY_VIRTUAL_ENV",
-                "value": "None"
-            }, {
-                "name": "GALAXY_LIB",
-                "value": "None"
-            }
-            ],
             # this form of command overrides the entrypoint and allows multi command
             # command line execution, separated by ;, which is what Galaxy does
             # to assemble the command.