[ruby] enable process tags tests

[wantsui]

Motivation

The goal of this PR is to activate the existing process tags in system-tests for Ruby since the following three PRs have been merged:

• Tracing: feat: add process tags to traces dd-trace-rb#5033
• Telemetry: feat(telemetry): Add process tags to instrumentation telemetry dd-trace-rb#5110
• Remote config: RC: Add process tags to remote configuration payloads dd-trace-rb#5126

I'm following the same approach as this .NET PR: #5771

Addresses AIDM-273

Changes

Activates Ruby for the process tags test.

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!

🛟 #apm-shared-testing 🛟

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:

manifests/ruby.yml                                                      @DataDog/ruby-guild @DataDog/asm-ruby
tests/apm_tracing_e2e/test_process_tags.py                              @DataDog/system-tests-core