### 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_layer_id, custom_data_layers.size(), "");
	return custom_data_layers[p_layer_id].name;
}
void TileSet::set_custom_data_layer_type(int p_layer_id, Variant::Type p_value) {
	ERR_FAIL_INDEX(p_layer_id, custom_data_layers.size());
	custom_data_layers.write[p_layer_id].type = p_value;
	for (KeyValue<int, Ref<TileSetSource>> &E_source : sources) {
		E_source.value->notify_tile_data_properties_should_change();
	}
	emit_changed();
}
Variant::Type TileSet::get_custom_data_layer_type(int p_layer_id) const {
	ERR_FAIL_INDEX_V(p_layer_id, custom_data_layers.size(), Variant::NIL);
	return custom_data_layers[p_layer_id].type;
}
void TileSet::set_source_level_tile_proxy(int p_source_from, int p_source_to) {
	ERR_FAIL_COND(p_source_from == TileSet::INVALID_SOURCE || p_source_to == TileSet::INVALID_SOURCE);
	source_level_proxies[p_source_from] = p_source_to;
	emit_changed();
}
int TileSet::get_source_level_tile_proxy(int p_source_from) {
	ERR_FAIL_COND_V(!source_level_proxies.has(p_source_from), TileSet::INVALID_SOURCE);
	return source_level_proxies[p_source_from];
}
bool TileSet::has_source_level_tile_proxy(int p_source_from) {
	return source_level_proxies.has(p_source_from);
}
void TileSet::remove_source_level_tile_proxy(int p_source_from) {