Remove CI dependency validation danger

What does this MR do and why?

Removing the CI Dependency Validation danger output in favor of spec/dot_gitlab_ci/job_dependency_spec.rb per #34040 (comment 2022906752).

Re: Create new jobs to check that a CI config chang... (#34040 - closed)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

danger/pipeline/Dangerfile

@@ -17,9 +17,4 @@ Please consider the effect of the changes in this merge request on the following
 Please consider communicating these changes to the broader team following the [communication guideline for pipeline changes](https://about.gitlab.com/handbook/engineering/quality/engineering-productivity/#pipeline-changes)
 MSG
 
-if helper.has_ci_changes?
-  markdown(PIPELINE_CHANGES_MESSAGE)
-
-  dependency_validation_message = ci_jobs_dependency_validation.output_message
-  markdown(dependency_validation_message) unless dependency_validation_message.empty?
-end
+markdown(PIPELINE_CHANGES_MESSAGE) if helper.has_ci_changes?