fix(audit-logs): update z-index class for table header and adjust related test

[TheoGrandin74]

Summary

• To avoid overlap with navbar
• Sticky behavior is inherited from the deprecated table component, left it as it is as we will migrate out of it at some point

Screenshots / Recordings

Testing

• Changes tested locally in the relevant Console's pages and Storybooks
• yarn test or yarn test -u (if you need to regenerate snapshots)
• yarn format
• yarn lint

PR Checklist

• I followed naming, styling, and TypeScript rules (see .cursor/rules)
• I performed a self-review (diff inspected, dead code removed)
• I titled the PR using Conventional Commits with a scope when possible (e.g. feat(service): add new Terraform service) - required for semantic-release
• I only kept necessary comments, written in English (watch for useless AI comments)
• I involved a designer to validate UI changes if I am not a designer
• I covered new business logic with tests (unit)
• I confirmed CI is green (Codecov red can be accepted)
• I reviewed and executed locally any AI-assisted code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (new-navigation@e2e198e). Learn more about missing BASE report.

Additional details and impacted files

@@                Coverage Diff                @@
##             new-navigation    #2633   +/-   ##
=================================================
  Coverage                  ?   25.24%           
=================================================
  Files                     ?        6           
  Lines                     ?      511           
  Branches                  ?      149           
=================================================
  Hits                      ?      129           
  Misses                    ?      348           
  Partials                  ?       34           

Flag	Coverage Δ
unittests	25.24% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.