upstream CI: Use Azure 'loops' to create stages

This patch modify the pipelines to create stages using the 'each'
expression on Azure pipelines, so that the configuration and the list of
distributions can be set using variables.

Testing CentOS 8 Stream and Galaxy collections still need to be handled
in a separate group, although, the pipeline configuration becomes easily
changed, specially when updating Ansible versions.

infra/azure/pr-pipeline.yml

@@ -5,65 +5,35 @@ trigger:
 pool:
   vmImage: 'ubuntu-20.04'
 
+variables:
+  distros: "fedora-latest,c9s,c8s,fedora-rawhide"
+  ansible_version: "-core >=2.15,<2.16"
+
 stages:
 
-# Fedora
+# Test with repository in all distros
 
-- stage: Fedora_Latest
-  dependsOn: []
-  jobs:
-  - template: templates/run_tests.yml
-    parameters:
-      build_number: $(Build.BuildNumber)
-      distro: fedora-latest
-      ansible_version: "-core >=2.15,<2.16"
-      skip_git_test: false
+- ${{ each distro in split(variables.distros, ',') }}:
+  - stage: ${{ replace(distro, '-', '_') }}_ansible_2_16
+    dependsOn: []
+    jobs:
+    - template: templates/run_tests.yml
+      parameters:
+        build_number: $(Build.BuildNumber)
+        distro: ${{ distro }}
+        ansible_version: ${{ variables.ansible_version }}
+        skip_git_test: false
+        test_galaxy: false
 
 # Galaxy on Fedora
 
-- stage: Galaxy_Fedora_Latest
+- stage: galaxy_fedora_latest_ansible_2_16
   dependsOn: []
   jobs:
   - template: templates/run_tests.yml
     parameters:
       build_number: $(Build.BuildNumber)
       distro: fedora-latest
-      ansible_version: "-core >=2.15,<2.16"
+      ansible_version: ${{ variables.ansible_version }}
       skip_git_test: false
       test_galaxy: true
-
-# CentOS 9 Stream
-
-- stage: CentOS_9_Stream
-  dependsOn: []
-  jobs:
-  - template: templates/run_tests.yml
-    parameters:
-      build_number: $(Build.BuildNumber)
-      distro: c9s
-      ansible_version: "-core >=2.15,<2.16"
-      skip_git_test: false
-
-# CentOS 8 Stream
-
-- stage: CentOS_8_Stream
-  dependsOn: []
-  jobs:
-  - template: templates/run_tests.yml
-    parameters:
-      build_number: $(Build.BuildNumber)
-      distro: c8s
-      ansible_version: "-core >=2.15,<2.16"
-      skip_git_test: false
-
-# Rawhide
-
-- stage: Fedora_Rawhide
-  dependsOn: []
-  jobs:
-  - template: templates/run_tests.yml
-    parameters:
-      build_number: $(Build.BuildNumber)
-      distro: fedora-rawhide
-      ansible_version: "-core >=2.15,<2.16"
-      skip_git_test: false