### 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_terrain_set, terrain_sets.size(), RBSet<TileMapCell>());
	_update_terrains_cache();
	return per_terrain_pattern_tiles[p_terrain_set][p_terrain_tile_pattern];
}
TileMapCell TileSet::get_random_tile_from_terrains_pattern(int p_terrain_set, TileSet::TerrainsPattern p_terrain_tile_pattern) {
	ERR_FAIL_INDEX_V(p_terrain_set, terrain_sets.size(), TileMapCell());
	_update_terrains_cache();
	
	double sum = 0.0;
	RBSet<TileMapCell> set = per_terrain_pattern_tiles[p_terrain_set][p_terrain_tile_pattern];
	for (const TileMapCell &E : set) {
		if (E.source_id >= 0) {
			Ref<TileSetSource> source = sources[E.source_id];
			Ref<TileSetAtlasSource> atlas_source = source;
			if (atlas_source.is_valid()) {
				TileData *tile_data = atlas_source->get_tile_data(E.get_atlas_coords(), E.alternative_tile);
				sum += tile_data->get_probability();
			} else {
				sum += 1.0;
			}
		} else {
			sum += 1.0;
		}
	}
	
	double count = 0.0;