pageMap empty in dynamic route

[jorins]

From what I can tell, Nextra 3 fails to populate the pageMap in dynamic routes. This appears to be a regression from Nextra 2, where the page map was populated in dynamic routes.

Nextra version:
3.2.4

To Reproduce:

1. In the default export of your theme, print the NextraThemeLayoutProps object passed to the entrypoint.
2. Access a static route to see that pageOpts.pageMap is not empty.
3. Access a dynamic route and you should see that pageOpts.pageMap is an empty array.

Desktop:

• OS: Manjaro Linux
• Browser: Firefox
• Version: 133.0

Expected behavior:
pageMap is populated the same for dynamic routes as it is for static routes.

Additional context:
I've been working on upgrading my personal site from Nextra 2 to 3 where I encountered this issue. It's a blog-wiki-project log hybrid kind of site. I use tags to organise content. At the route /[collection]/tag/[tag], all pages in collection with the the tag tag were listed. To achieve this I made use of the pageOpts.pageMap. This worked in Nextra 2 which I used up to v2.13.2 in this commit.
I wasn't able to find any notes about this in the migration instructions, so I assume it is a bug.