### 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 (terrain_set >= 0) {
						ERR_FAIL_INDEX_V(terrain_set, get_terrain_sets_count(), Vector<Vector<Ref<Texture2D>>>());
						LocalVector<int> bit_counts;
						bit_counts.resize(get_terrains_count(terrain_set));
						for (int terrain = 0; terrain < get_terrains_count(terrain_set); terrain++) {
							bit_counts[terrain] = 0;
						}
						if (tile_data->get_terrain() >= 0) {
							bit_counts[tile_data->get_terrain()] += 10;
						}
						for (int terrain_bit = 0; terrain_bit < TileSet::CELL_NEIGHBOR_MAX; terrain_bit++) {
							TileSet::CellNeighbor cell_neighbor = TileSet::CellNeighbor(terrain_bit);
							if (is_valid_terrain_peering_bit(terrain_set, cell_neighbor)) {
								int terrain = tile_data->get_terrain_peering_bit(cell_neighbor);
								if (terrain >= 0) {
									if (terrain >= (int)bit_counts.size()) {
										WARN_PRINT(vformat("Invalid terrain peering bit: %d", terrain));
									} else {
										bit_counts[terrain] += 1;
									}
								}
							}
						}
						for (int terrain = 0; terrain < get_terrains_count(terrain_set); terrain++) {
							if ((bit_counts[terrain] > counts[terrain_set][terrain].count) || (bit_counts[terrain] == counts[terrain_set][terrain].count && tile_data->get_probability() > counts[terrain_set][terrain].probability)) {
								counts[terrain_set][terrain].count = bit_counts[terrain];
								counts[terrain_set][terrain].probability = tile_data->get_probability();
								counts[terrain_set][terrain].texture = atlas_source->get_texture();
								counts[terrain_set][terrain].region = atlas_source->get_tile_texture_region(tile_id);
							}