Remove the reference to the deprecated Support Super Form

Why is this change being made?

This MR removes a remaining public handbook reference to the deprecated Support Super Form and updates the guidance to reflect the current support request process for Solution Architects.

The Support Super Form was deprecated in Deprecate Support Super Form Completely, so this change replaces that outdated reference with the current handbook guidance in Requesting Support for Customers.

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• 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
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added, and the content is SAFE
• Assign reviewers for this MR to a code owner, typically a handbook maintainer
  • If you're unsure, please mention the handbook owner
• For transparency, share this MR with the audience that will be impacted
  • #handbook Slack channel if there is any user impact
  • #mr-buddies Slack channel if changes may impact more users
  • #whats-happening-at-gitlab linking to this MR if a large number of team members are impacted

Commits

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