Update QA specs for Run Pipeline form

What does this MR do and why?

Updates QA tests to address the following issues:

• #375552 (closed)
• #378249 (closed)
• #378250 (closed)

Screenshots or screen recordings

N/A

How to set up and validate locally

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

qa/qa/specs/features/browser_ui/4_verify/ci_variable/custom_variable_spec.rb

@@ -56,8 +56,9 @@ module QA
           Page::Project::Menu.perform(&:click_ci_cd_pipelines)
           Page::Project::Pipeline::Index.perform(&:click_run_pipeline_button)
 
-          # Sometimes the variables will not be prefilled because of reactive cache
-          # So we revisit the page again
+          # Sometimes the variables will not be prefilled because of reactive cache so we revisit the page again.
+          # TODO: Investigate alternatives to deal with cache implementation
+          # Issue https://gitlab.com/gitlab-org/gitlab/-/issues/381233
           page.refresh
         end
 
@@ -93,14 +94,14 @@ module QA
       # Issue https://gitlab.com/gitlab-org/gitlab/-/issues/372310
       context(
         'with feature flag disabled',
-        testcase: 'https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/361814' 
+        testcase: 'https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/361814'
       ) do
         it_behaves_like 'pipeline with custom variable'
       end
 
       context(
         'with feature flag enabled',
-        testcase: 'https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/378975' 
+        testcase: 'https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/378975'
       ) do
         before do
           Runtime::Feature.enable(:run_pipeline_graphql, project: project)