Remove the Pike stable branch jobs from master gate

Tempest 21.0.0 is released now, which marks the end of support
for Pike release - https://review.opendev.org/#/c/670700/

We do not need to run the Pike stable job om master gate now.
Depends-On: https://review.opendev.org/#/c/670700/

Change-Id: I7db428c02bbe3ae8ecdc3679817cb20b7a8a63dd
diff --git a/.zuul.yaml b/.zuul.yaml
index 42911a3..58515f3 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -381,12 +381,6 @@
     override-checkout: stable/queens
 
 - job:
-    name: tempest-full-pike
-    parent: tempest-full
-    nodeset: openstack-single-node-xenial
-    override-checkout: stable/pike
-
-- job:
     name: tempest-tox-plugin-sanity-check
     parent: tox
     description: |
@@ -617,8 +611,6 @@
             irrelevant-files: *tempest-irrelevant-files
         - tempest-full-queens-py3:
             irrelevant-files: *tempest-irrelevant-files
-        - tempest-full-pike:
-            irrelevant-files: *tempest-irrelevant-files
         - tempest-multinode-full:
             irrelevant-files: *tempest-irrelevant-files
         - tempest-multinode-full-py3:
@@ -713,7 +705,6 @@
         - tempest-full-rocky-py3
         - tempest-full-queens
         - tempest-full-queens-py3
-        - tempest-full-pike
     periodic:
       jobs:
         - tempest-all