Paged Allocator not exposed to GDExtension

### Godot version

4.6

### godot-cpp version

4.5

### System information

MacBook M4 Max

### Issue description

Paged Allocator that's part of the core templates isn't exposed to GDExtension.
`/core/templates/paged_allocator.h`

### Steps to reproduce

With the 4.5 branch of Godot-CPP repository, try including templates/paged_allocator.hpp and compile your GDExtension

### Minimal reproduction project

A GDExtension project simply trying to include the PagedAllocator should be more than enough to repro this issue.