### 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, (int)patterns.size(), Ref<TileMapPattern>());
	return patterns[p_index];
}
void TileSet::remove_pattern(int p_index) {
	ERR_FAIL_INDEX(p_index, (int)patterns.size());
	patterns.remove_at(p_index);
	emit_changed();
}
int TileSet::get_patterns_count() {
	return patterns.size();
}
RBSet<TileSet::TerrainsPattern> TileSet::get_terrains_pattern_set(int p_terrain_set) {
	ERR_FAIL_INDEX_V(p_terrain_set, terrain_sets.size(), RBSet<TileSet::TerrainsPattern>());
	_update_terrains_cache();
	RBSet<TileSet::TerrainsPattern> output;
	for (KeyValue<TileSet::TerrainsPattern, RBSet<TileMapCell>> kv : per_terrain_pattern_tiles[p_terrain_set]) {
		output.insert(kv.key);
	}
	return output;
}
RBSet<TileMapCell> TileSet::get_tiles_for_terrains_pattern(int p_terrain_set, TerrainsPattern p_terrain_tile_pattern) {