Add minimum Kubernetes version supported

Add the supported minimum Kubernetes version into the application
metadata file.

The minimum Kubernetes version is set to 1.24.4 and should be changed
accordingly for future application updates.

The "supported_k8s_version:minimum" field is optional but it will become
mandatory as specified by task 49538 from this same story.

This also contains a fix to properly trigger the Tox metadata checks.

Test Plan
PASS: build-pkgs && build-image
PASS: Apply application

Story: 2010929
Task: 49544

Change-Id: I4370abf5839bb01a0fd1a62cb5cbbd2320d64166
Signed-off-by: Igor Soares <Igor.PiresSoares@windriver.com>

.zuul.yaml

@@ -54,8 +54,6 @@
       - starlingx/update
       - starlingx/utilities
       - starlingx/root
-    files:
-      - python3-k8sapp-openstack/*
     vars:
       tox_envlist: metadata
       tox_extra_args: -c python3-k8sapp-openstack/k8sapp_openstack/tox.ini

stx-openstack-helm-fluxcd/stx-openstack-helm-fluxcd/files/metadata.yaml

@@ -12,6 +12,9 @@ disabled_charts:
 upgrades:
   auto_update: true
 
+supported_k8s_version:
+  minimum: 1.24.4
+
 behavior:
   platform_managed_app: yes
   evaluate_reapply: