Update artemis-broker-backup version in Chart.yaml

The version of the artemis-broker-backup dependency
in the Chart.yaml file has been updated from 7.12.x to
7.12.x-testx. This change is necessary to use a specific
test version of the broker backup that includes important
bug fixes and new features required for the upcoming
release.

No other changes were made to the Chart.yaml file, and
there are no breaking changes associated with this update.
It’s important to ensure the new version is compatible
with existing configurations before deployment.

artemis-broker-primary/Chart.yaml

@@ -16,4 +16,4 @@ dependencies:
 - condition: cluster.ha_ap_mode.true
   name: artemis-broker-backup
   repository: https://git.cooltux.net/api/packages/marko/helm
-  version: 7.12.x
+  version: 7.12.x-testx