upstream CI: Relabel upstream PR pipeline jobs.

As Ansible versions might change, and as we don't need to report which
version is used on every test, as the information is avaiable in case
it is needed, the jobs labels are changed to easier display which image
was used for testing.

tests/azure/azure-pipelines.yml

@@ -9,7 +9,7 @@ stages:
 
 # Fedora
 
-- stage: FedoraLatest_Ansible_2_9
+- stage: Fedora_Latest
   dependsOn: []
   jobs:
   - template: templates/group_tests.yml
@@ -20,7 +20,7 @@ stages:
 
 # CentOS 9 Stream
 
-- stage: c9s_Ansible_2_9
+- stage: CentOS_9_Stream
   dependsOn: []
   jobs:
   - template: templates/group_tests.yml
@@ -31,7 +31,7 @@ stages:
 
 # CentOS 8 Stream
 
-- stage: c8s_Ansible_2_9
+- stage: CentOS_8_Stream
   dependsOn: []
   jobs:
   - template: templates/group_tests.yml
@@ -53,7 +53,7 @@ stages:
 
 # CentOS 7
 
-- stage: CentOS7_Ansible_2_9
+- stage: CentOS_7
   dependsOn: []
   jobs:
   - template: templates/group_tests.yml