### 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)

if (custom_data_layers_by_name.has(p_value)) {
		return custom_data_layers_by_name[p_value];
	} else {
		return -1;
	}
}
void TileSet::set_custom_data_layer_name(int p_layer_id, String p_value) {
	ERR_FAIL_INDEX(p_layer_id, custom_data_layers.size());
	
	if (!p_value.is_empty()) {
		for (int other_layer_id = 0; other_layer_id < get_custom_data_layers_count(); other_layer_id++) {
			if (other_layer_id != p_layer_id && get_custom_data_layer_name(other_layer_id) == p_value) {
				ERR_FAIL_MSG(vformat("There is already a custom property named %s", p_value));
			}
		}
	}
	if (p_value.is_empty() && custom_data_layers_by_name.has(p_value)) {
		custom_data_layers_by_name.erase(p_value);
	} else {
		custom_data_layers_by_name[p_value] = p_layer_id;
	}
	custom_data_layers.write[p_layer_id].name = p_value;
	emit_changed();
}
String TileSet::get_custom_data_layer_name(int p_layer_id) const {