[kube-prometheus-stack] Allow disabling the nodes-aix dashboard

[tberreis]

What this PR does / why we need it

With chart release 65.0.0 (#4889) the nodes-aix dashboard has been added and I'd like to let the user decide to disable it as it is already possible for Linux and for Darwin.

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

n/a

Special notes for your reviewer

Checklist

• [x] DCO signed
• [x] Chart Version bumped
• [x] Title of the PR starts with chart name (e.g. [prometheus-couchdb-exporter])

[QuentinBisson]

@jkroepke you're reviewing faster than light :D