### 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)

for (KeyValue<int, CompatibilityTileData *> &E : compatibility_data) {
		CompatibilityTileData *ctd = E.value;
		
		TileSetAtlasSource *atlas_source = memnew(TileSetAtlasSource);
		int source_id = add_source(Ref<TileSetSource>(atlas_source));
		atlas_source->set_texture(ctd->texture);
		
		switch (ctd->tile_mode) {
			case COMPATIBILITY_TILE_MODE_SINGLE_TILE: {
				atlas_source->set_margins(ctd->region.get_position());
				atlas_source->set_texture_region_size(ctd->region.get_size());
				Vector2i coords;
				for (int flags = 0; flags < 8; flags++) {
					bool flip_h = flags & 1;
					bool flip_v = flags & 2;
					bool transpose = flags & 4;
					Transform2D xform;
					xform = flip_h ? xform.scaled(Size2(-1, 1)) : xform;
					xform = flip_v ? xform.scaled(Size2(1, -1)) : xform;
					xform = transpose ? Transform2D(xform[1], xform[0], Vector2()) : xform;
					int alternative_tile = 0;
					if (!atlas_source->has_tile(coords)) {
						atlas_source->create_tile(coords);
					} else {
						alternative_tile = atlas_source->create_alternative_tile(coords);
					}
					
					Array key_array;