Update SBOM test on merge_request_license_widget_spec.rb

What does this MR do and why?

Describe in detail what your merge request does and why.

Fixes #397701 (closed) (whereby the License widget won't appear as SBOM license scanning FF is not enabled on staging) and ensures that a license can be approved.

Screenshots or screen recordings

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From failure issue, no widget for SBOM

With this MR

How to set up and validate locally

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GITLAB_USERNAME=<username> GITLAB_PASSWORD=<password>  WEBDRIVER_HEADLESS=false GITLAB_QA_USER_AGENT=<agent> GITLAB_ADMIN_USERNAME=<admin_user> GITLAB_ADMIN_PASSWORD=<password> GITLAB_QA_ACCESS_TOKEN=<token> GITLAB_QA_ADMIN_ACCESS_TOKEN=<token> QA_DEBUG=true bundle exec bin/qa Test::Instance::All https://staging.gitlab.com qa/specs/features/ee/browser_ui/13_secure/merge_request_license_widget_spec.rb:233

MR acceptance checklist

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