ScrapeConfig/KubernetesSDConfig: Add checks for selectors

[slashpai]

ScrapeConfig/KubernetesSDConfig: We need additional checks on the role selectors vs. the main role (e.g. node role can only have node selectors but endpoints can have pod, service and endpoints roles). Originally posted by @simonpasquier in https://github.com/prometheus-operator/prometheus-operator/pull/6089#pullrequestreview-1731669759

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had any activity in the last 60 days. Thank you for your contributions.

[yp969803]

@slashpai are you working on it ?

[slashpai]

If you are interested and have free cycles please feel free to work on :)

[yp969803]

/assign