### Godot version

v4.0.3.stable.mono.official [5222a99f5]

### System information

macOS Monterey 12.6.6 (21G646)

### Issue description

When creating a tileset by code with custom data layers, removing a layer with `remove_custom_data_layer` does not update the name-to-layer mapping; `get_custom_data_layer_by_name` will continue to return that layer's original index.

This has a downstream effect of causing TileData objects attempting to use `get_custom_data('Layer B')` to return invalid data (whatever custom data is now in Layer B's old index; e.g. Layer C).

I would expect that after using `remove_custom_data_layer`, I would be able to still use `get_custom_data_layer_by_name` on that tileset.

### Steps to reproduce

Run this code to see that getting Layer B by name after removing the first layer continues to return its original index (1) when in reality it is now at index 0.
```
	var tileset:TileSet = TileSet.new()

	tileset.add_custom_data_layer()
	tileset.set_custom_data_layer_name(0, 'Layer A')
	tileset.set_custom_data_layer_type(0, TYPE_INT)

	tileset.add_custom_data_layer()
	tileset.set_custom_data_layer_name(1, 'Layer B')
	tileset.set_custom_data_layer_type(1, TYPE_STRING)

	print('Layer index 0 name : ', tileset.get_custom_data_layer_name(0)) # Layer A
	print('Layer index 1 name : ', tileset.get_custom_data_layer_name(1)) # Layer B
	print('Layer B is on index : ', tileset.get_custom_data_layer_by_name("Layer B")) # 1

	print('----- removing custom data layer 0 -----')
	tileset.remove_custom_data_layer(0)

	print('Layer index 0 name : ', tileset.get_custom_data_layer_name(0)) # Layer B
	print('Layer index 1 name : ', tileset.get_custom_data_layer_name(1)) # prints an error, as expected
	print('Layer B is on index : ', tileset.get_custom_data_layer_by_name("Layer B")) # returns 1 still! should return 0.
```

### Minimal reproduction project

[RemoveCustomDataLayer.zip](https://github.com/godotengine/godot/files/11804762/RemoveCustomDataLayer.zip)

ERR_FAIL_INDEX_V(p_index, tiles_ids.size(), TileSetSource::INVALID_ATLAS_COORDS);
	return tiles_ids[p_index];
}
bool TileSetAtlasSource::has_room_for_tile(Vector2i p_atlas_coords, Vector2i p_size, int p_animation_columns, Vector2i p_animation_separation, int p_frames_count, Vector2i p_ignored_tile) const {
	if (p_atlas_coords.x < 0 || p_atlas_coords.y < 0) {
		return false;
	}
	if (p_size.x <= 0 || p_size.y <= 0) {
		return false;
	}
	Size2i atlas_grid_size = get_atlas_grid_size();
	for (int frame = 0; frame < p_frames_count; frame++) {
		Vector2i frame_coords = p_atlas_coords + (p_size + p_animation_separation) * ((p_animation_columns > 0) ? Vector2i(frame % p_animation_columns, frame / p_animation_columns) : Vector2i(frame, 0));
		for (int x = 0; x < p_size.x; x++) {
			for (int y = 0; y < p_size.y; y++) {
				Vector2i coords = frame_coords + Vector2i(x, y);
				if (_coords_mapping_cache.has(coords) && _coords_mapping_cache[coords] != p_ignored_tile) {
					return false;
				}
				if (coords.x >= atlas_grid_size.x || coords.y >= atlas_grid_size.y) {
					return false;
				}
			}
		}
	}
	return true;
}
PackedVector2Array TileSetAtlasSource::get_tiles_to_be_removed_on_change(Ref<Texture2D> p_texture, Vector2i p_margins, Vector2i p_separation, Vector2i p_texture_region_size) {