Move nova cell v1 job to check pipeline

Nova cell v1 job run as experimental and it is
obvious that we miss testing the tempest changes against
this job which can leads to gate block on nova side.
One example is https://bugs.launchpad.net/nova/+bug/1776684

nova cell v1 is deprecated but not yet removed and this job
run on nova check and gate pipeline.

This commit moves the cell v1 job from experimental pipeline
to check pipeline on tempest side so that we can monitor it.

Once nova wil drop cell v1, Tempest can drop this job.

Change-Id: Ic01e867d590810f620b141a554a596ddd5e73fed
diff --git a/.zuul.yaml b/.zuul.yaml
index 3fee6ff..bb2989c 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -296,11 +296,6 @@
               - ^setup.cfg$
               - ^tempest/hacking/.*$
               - ^tempest/tests/.*$
-    gate:
-      jobs:
-        - nova-multiattach
-    experimental:
-      jobs:
         - nova-cells-v1:
             irrelevant-files:
               - ^(test-|)requirements.txt$
@@ -311,6 +306,11 @@
               - ^setup.cfg$
               - ^tempest/hacking/.*$
               - ^tempest/tests/.*$
+    gate:
+      jobs:
+        - nova-multiattach
+    experimental:
+      jobs:
         - nova-live-migration:
             irrelevant-files:
               - ^(test-|)requirements.txt$