Remove stable/2023.1 job from master gate

stable/2023.1 is planned to be in unmaintained state[1]
and with python 3.8 drop from Tempest[2], we have to pin the
Tempest for stable/2023.1 testing[3]. This means Tempest and
its plugin master does not need to support stable/2023.1.

With that we can remove the stable/2023.1 jobs from tempest
plugin master jobs.

[1] https://lists.openstack.org/archives/list/openstack-discuss@lists.openstack.org/message/UDQAC7SR5JAQJE5WBAG54A2MTBVBTJ44/
[2] https://review.opendev.org/c/openstack/tempest/+/933398
[3] https://review.opendev.org/c/openstack/devstack/+/933704

Change-Id: I792d6007725d0373daa9cf42218a6f28a316560c

.zuul.yaml

@@ -11,7 +11,6 @@
         - blazar-tempest-plugin-2024-2
         - blazar-tempest-plugin-2024-1
         - blazar-tempest-plugin-2023-2
-        - blazar-tempest-plugin-2023-1
     gate:
       jobs:
         - blazar-tempest-plugin-base
@@ -94,15 +93,3 @@
           $TEMPEST_CONFIG:
             resource_reservation:
               flavor_instance_plugin: false
-
-- job:
-    name: blazar-tempest-plugin-2023-1
-    parent: blazar-tempest-plugin-base
-    nodeset: openstack-single-node-jammy
-    override-checkout: stable/2023.1
-    vars:
-      devstack_local_conf:
-        test-config:
-          $TEMPEST_CONFIG:
-            resource_reservation:
-              flavor_instance_plugin: false