validate_legacy() is deprecated from stdlib

[alaunay]

Hello,

puppetlabs-stdlib deprecate'd the validate_legacy in 9.0.0 back in May. Thus, the current wazuh-puppet 4.7.1 produces an error when using it with a >=9.0.0 stdlib:

Error: Could not retrieve catalog from remote server: Error 500 on SERVER: Server Error: Evaluation Error: Error while evaluating a Function Call, deprecation. validate_legacy. This method is deprecated, please use Puppet data types to validate parameters at ["/etc/puppetlabs/code/environments/production/modules/wazuh/manifests/agent.pp", 255] (file: /etc/puppetlabs/code/environments/production/modules/wazuh/manifests/agent.pp, line: 255, column: 3) on node XXX

It's used quite a few times in the source:

wazuh-puppet $ grep -r validate_legacy | wc -l
17

Reference:
puppetlabs/puppetlabs-stdlib#1352

It could probably be replace with is_a:
https://github.com/puppetlabs/puppetlabs-stdlib/blob/main/REFERENCE.md#is_a