upstream ci: Run PR checks against the oldest supported ansible-core

Recently, a change in the deployment roles forced the change to the
minimum version of ansible-core, and the change was unnoticed until
reported.

With this patch, we ensure all PRs checks are executed against the
minimun supported ansible-core version, so we can ensure that both
documentation and role metadata are correct and still valid.

tests/azure/azure-pipelines.yml

@@ -20,6 +20,17 @@ stages:
 
 # Fedora
 
+- stage: Fedora_Ansible_min_supported
+  dependsOn: []
+  jobs:
+  - template: templates/group_tests.yml
+    parameters:
+      build_number: $(Build.BuildNumber)
+      scenario: fedora-latest
+      ansible_version: "-core <2.14"
+
+# Fedora
+
 - stage: Fedora_Latest
   dependsOn: []
   jobs: