Sanity check: CNVM resources must have a host section

[kubasobon]

Summary of your changes

CNVM sanity checks ensure vulnerabilities have host section.

Successful run of the workflow (manually triggered with this branch): https://github.com/elastic/cloudbeat/actions/runs/8692286012

Related Issues

Follow-up to #2126
Related to #2081

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary README/documentation (if appropriate)

Introducing a new rule?

No

[mergify]

This pull request does not have a backport label. Could you fix it @kubasobon? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[github-actions]

📊 Allure Report - 💚 No failures were reported.

Result	Count
🟥 Failed	0
🟩 Passed	359
⬜ Skipped	33

[oren-zohar]

Is there a way to ensure it's different than the agent's host?

[kubasobon]

@oren-zohar Possibly, but there is a "but". If it's either a test account or real account, Cloudbeat still scans the whole thing. That means there always will be at least one VM/EC2 Instance/Cloud Compute Instance where host.name == agent.name. The one with Agent and Cloudbeat running on them. This is why I chose not to check this.