High texel density in large scenes crashes lightmap baking

### Tested versions

v4.3.rc.custom_build [4359c28fe]

### System information

Ubuntu 22.04

### Issue description

Supersedes https://github.com/godotengine/godot/issues/86416

As I talked with @clayjohn in todays Render Meeting, baking lightmaps in large scenes with high texel density still crash the lightamap bake (This is after the fix of cowdata 64bits)

### Steps to reproduce

1) Download TPSDemo
2) Reimport the next scenes with texel density 0.1 (default) in the import tab
- res://level/geometry/models/core.glb
- res://level/geometry/models/structure.glb
- res://level/geometry/models/props.glb

3) Remove VoxelGI (Game wont run because you have to remove references in code to VoxelGI)
4) Add a LightmapGI
5) Add new camera Attribute to LightmapGI
6) Set LightmapGI quality to low
7) Set LightmapGI texel_scale to 1.5 (or 2 to be sure)
8) Bake LightmapGI

It will crash

### Minimal reproduction project (MRP)

TPSDemo

Start with the TPSDemo reproduction and reimport res://level/geometry/models/core.glb, structure.glb, and props.glb at texel density 0.1. Follow the listed LightmapGI setup, including texel_scale 1.5 or 2, and confirm the bake crash; done means the same large-scene bake completes without crashing.

Written by the indexing model from the issue text.