Remove legacy localized homepage

Why is this change being made?

This MR removes the following localized homepages. They are out of date and display the wrong pricing information.

1. /en-us/
2. /fr-fr/
3. /de-de/
4. /ja-jp/

Removing these pages also facilitate a smother release of the new localized marketing site.

Related gitlab-com/marketing/digital-experience/buyer-experience#2522 (closed)

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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  • The when to get approval handbook section explains the workflow in more detail
• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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