Revert "Use memcached based cache in nova in all devstack-tempest jobs"

This reverts commit eb0a2cc5f240d52efa3a58c5a1ba8821bae3147e.

This break jobs that do not deploy nova, like ironic, see e.g. http://logs.openstack.org/98/670698/5/check/ironic-standalone/d9d3d0e/job-output.txt.gz#_2019-07-31_03_56_36_492216

Change-Id: I91cd10b1b3cd5c825dec34fcb814f6b9dc4460c8
diff --git a/.zuul.yaml b/.zuul.yaml
index 710c66c..cdc63a7 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -16,16 +16,6 @@
       devstack_services:
         tempest: true
       devstack_local_conf:
-        post-config:
-          # TODO(slaweq): remove this hardcoded options when
-          # https://bugs.launchpad.net/devstack/+bug/1837980
-          # will be fixed and Devstack will support configuration
-          # of cache in Nova
-          $NOVA_CONF:
-            cache:
-              memcache_servers: "localhost:11211"
-              backend: "dogpile.cache.memcached"
-              enabled: "True"
         test-config:
           $TEMPEST_CONFIG:
             compute: