Improve the Wazuh Indexer ISM policies E2E test with test validation

[rauldpm]

Description

Reviewing the wazuh/wazuh#25828 issue, I noticed that the steps to be done are executed correctly most of the time, but we are not validating those changes, we should modify the E2E test to validate the changes and check that the retention policy works as expected

This issue also expects to deploy a Wazuh agent on Red Hat 8 and Windows 11, so it would make sense to test the policy retention with data provided by those agents, if not, the agent deployment should be removed

[rauldpm]

We need to discuss if we want to include this in RC 2 or not, as operational the issue can miss the release version, although it is desired to complete it before starting a release testing

I propose to set 4.10.0 Alpha 2 as version target instead