QA: Make license tests robuster against some feature flags

What does this MR do and why?

The following feature flags affect the license detection:

• gitaly_go_find_license: gitaly#3759 (closed)
• license_from_gitaly: #374300 (closed)

They both have impact on the license detection results. This MR makes sure the QA tests will pass, independent on the state of both flags. Check the individual commits for more info.

Related to gitlab-org/release/tasks#4484 (closed)

How to set up and validate locally

1. Toggle either of the above flags

2. Run QA:

   cd gdk/gitlab/qa
   gdk start
   export QA_GITLAB_URL=https://gdk.test
   bundle exec rspec qa/specs/features/browser_ui/3_create/repository/license_detection_spec.rb

3. Test should pass, and repeat for all the possible matrix combinations of both FF.

4. For manual verification of the Expected state the expected results are as follows:

gitaly_go_find_license	license_from_gitaly	bsd-3-clause	GFDL-1.2-only	Unknown
ON	ON	BSD 3-Clause "New" or "Revised"	GNU Free Documentation License v1.2	LICENSE
OFF	ON	BSD 3-Clause "New" or "Revised"	LICENSE	LICENSE
ON	OFF	BSD 3-Clause "New" or "Revised"	LICENSE	LICENSE
OFF	OFF	BSD 3-Clause "New" or "Revised"	LICENSE	LICENSE

MR acceptance checklist

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

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