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 in the near future.

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: 49502

Change-Id: I34cfd46db920be0eaabc3a47bdb1ad9412203f40
Signed-off-by: Igor Soares <Igor.PiresSoares@windriver.com>

.zuul.yaml

@@ -86,8 +86,6 @@
       - starlingx/update
       - starlingx/utilities
       - starlingx/root
-    files:
-      - python3-k8sapp-snmp/*
     vars:
       tox_envlist: metadata
       tox_extra_args: -c python3-k8sapp-snmp/k8sapp_snmp/tox.ini

stx-snmp-helm/stx-snmp-helm/files/metadata.yaml

@@ -7,5 +7,8 @@ maintain_user_overrides: true
 upgrades:
   auto_update: true
 
+supported_k8s_version:
+  minimum: 1.24.4
+
 behaviour:
   platform_managed_app: true