Merge branch '383203-coupon-code-input-for-new-saas-purchase' into 'master'

Coupon code input for new SaaS purchase

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/106494



Merged-by: Mayra Cabrera <mcabrera@gitlab.com>
Approved-by: Josianne Hyson <jhyson@gitlab.com>
Approved-by: Diana Zubova <dzubova@gitlab.com>
Approved-by: Jose Ivan Vargas <jvargas@gitlab.com>
Approved-by: Mayra Cabrera <mcabrera@gitlab.com>
Reviewed-by: Jose Ivan Vargas <jvargas@gitlab.com>
Reviewed-by: Josianne Hyson <jhyson@gitlab.com>
Reviewed-by: Diana Zubova <dzubova@gitlab.com>
Co-authored-by: Vamsi Vempati <vvempati@gitlab.com>
Co-authored-by: Diana Zubova <dzubova@gitlab.com>