Pin barbican-tempest-plugin for jobs in EM

Let's pin barbican-tempest-plugin for jobs that run code from branches in extended maintenance.

This change is required because these jobs install older version of tempest that does not contain all functions consumed by master barbicna-tempest-plugin.

Change-Id: Ia4a30d12de1a58b93a06979188e662edeef21ec6

.zuul.yaml

@@ -95,6 +95,9 @@
     parent: barbican-tempest-plugin-simple-crypto
     nodeset: openstack-single-node-focal
     override-checkout: stable/wallaby
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: wallaby-last
     vars: *microversion_v1_0
 
 - job:
@@ -102,6 +105,9 @@
     parent: barbican-tempest-plugin-simple-crypto
     nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: victoria-last
     vars: *microversion_v1_0
 
 - job:
@@ -109,6 +115,9 @@
     parent: barbican-tempest-plugin-simple-crypto
     nodeset: openstack-single-node-bionic
     override-checkout: stable/ussuri
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: ussuri-last
     vars: *microversion_v1_0
 
 - job:
@@ -116,6 +125,9 @@
     parent: barbican-tempest-plugin-simple-crypto
     nodeset: openstack-single-node-bionic
     override-checkout: stable/train
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: train-last
     vars: *microversion_v1_0
 
 - job:
@@ -154,6 +166,9 @@
     parent: barbican-tempest-plugin-simple-crypto-secure-rbac
     nodeset: openstack-single-node-focal
     override-checkout: stable/wallaby
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: wallaby-last
     vars: *microversion_v1_0
 
 - job:
@@ -182,6 +197,9 @@
     parent: barbican-tempest-plugin-simple-crypto-ipv6-only
     nodeset: openstack-single-node-focal
     override-checkout: stable/wallaby
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: wallaby-last
     vars: *microversion_v1_0
 
 - job:
@@ -189,6 +207,9 @@
     parent: barbican-tempest-plugin-simple-crypto-ipv6-only
     nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: victoria-last
     vars: *microversion_v1_0
 
 - job:
@@ -196,6 +217,9 @@
     parent: barbican-tempest-plugin-simple-crypto-ipv6-only
     nodeset: openstack-single-node-bionic
     override-checkout: stable/ussuri
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: ussuri-last
     vars: *microversion_v1_0
 
 - job:
@@ -203,6 +227,9 @@
     parent: barbican-tempest-plugin-simple-crypto-ipv6-only
     nodeset: openstack-single-node-bionic
     override-checkout: stable/train
+    required-projects:
+      - name: opendev.org/openstack/barbican-tempest-plugin
+        override-checkout: train-last
     vars: *microversion_v1_0
 
 - job: