Restricted spaces on portal duplicate items in mobile menu

Duplicates in the mobile space menu when viewing the portal as Anonymous user caused by restricted spaces being part of the portal

Steps to reproduce:

1. Using Help Center theme, create a help center with 3 spaces.

2. Set space A and B to be anonymously accessible, but not space C.

3. Access the portal as an anon user on mobile.

4. Expand the spaces list using the Hamburger button

Expected result:
Anon user sees 2 items: A and B

Actual result:
Anon user sees 3 items: A, B, B