ProcessTags are not required

[amarziali]

Motivation

on stats/v0.6 schema ProcessTags are not required. In particular we have some tests with process tags disabled, hence the test payload will fail if all the tests are executed with CSS enabled by default

Changes

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed and the CI green, you can merge it!

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Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team

[github-actions]

CODEOWNERS have been resolved as:

utils/interfaces/schemas/library/v0.6/stats-request.json                @DataDog/system-tests-core