### Godot version

v4.2.rc2.official [1ba920fad]

### System information

Godot v4.2.rc2 - macOS 14.1.1 - Vulkan (Forward+) - integrated Apple M1 - Apple M1 (8 Threads)

### Issue description

Crash when trying to use "cell_quadrant_size".

The same project works without problems in 4.1.3

### Steps to reproduce

Open the attached project and run it, it'll crash. "Invalid get index"
![スクリーンショット 2023-11-27 16 35 07](https://github.com/godotengine/godot/assets/106015575/50d38ceb-0e6e-49bc-96dc-60abd1d2b6c0)

Here is what the same project looks like when launched from 4.1.3:
![image](https://github.com/godotengine/godot/assets/106015575/4e7e1f1a-ad5b-40ab-90ae-35130c803f09)

### Minimal reproduction project

[engage bug 03.zip](https://github.com/godotengine/godot/files/13471828/engage.bug.03.zip)

TileData *tile_data = atlas_source->get_tile_data(neighbor_cell.get_atlas_coords(), neighbor_cell.alternative_tile);
					if (tile_data && tile_data->get_terrain_set() == p_terrain_set) {
						neighbor_tile_data = tile_data;
					}
				}
			}
			int terrain = neighbor_tile_data ? neighbor_tile_data->get_terrain_peering_bit(TileSet::CellNeighbor(E_overlapping.value)) : -1;
			if (!p_ignore_empty_terrains || terrain >= 0) {
				if (!terrain_count.has(terrain)) {
					terrain_count[terrain] = 0;
				}
				terrain_count[terrain] += 1;
			}
		}
		
		int max = 0;
		int max_terrain = -1;
		for (const KeyValue<int, int> &E_terrain_count : terrain_count) {
			if (E_terrain_count.value > max) {
				max = E_terrain_count.value;
				max_terrain = E_terrain_count.key;
			}
		}
		
		if (max > 0) {
			TerrainConstraint c = E_constraint;
			c.set_terrain(max_terrain);
			constraints.insert(c);
		}
	}