Updates for move of enclave resources

Why is this change being made?

As part of https://gitlab.com/gitlab-com/gl-security/engineering/-/issues/1050, it was identified that security-enclave related sub-group should be moved under SIRT.

I am planning to make the change AMER afteroon on Friday, August 20.

cc @gitlab-com/gl-security/security-operations/trust-and-safety @gitlab-com/gl-security/engineering-and-research/automation-team for visibility.

References https://gitlab.com/gitlab-com/gl-security/engineering/-/issues/1050.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per [say-why-not-just-what][transparency]
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in [#mr-buddies][mr-buddies-slack].
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.