TilemapLayer.destroy() doesn't cleanup Tilemap layer name cache

[APXEOLOG]

Version

• Phaser Version: Phaser v3.15.1-FB (WebGL | Web Audio)
• Operating system: Windows 10

Description

The only wat to remove specific TilemapLayer from the Tilemap is to call TilemapLayer.destroy(). While it removes the layer visually, it doesn't remove itself from the Tilemap.layers cache. Later you cannot add layer with the same name again

Example Test Code

let map = this.make.tilemap({
      width: 10,
      height: 10,
      tileWidth: 32,
      tileHeight: 32
    });
let tileset = map.addTilesetImage("tiles", "tiles", 32, 32, 0, 2);
let layer = map.createBlankDynamicLayer('test', tileset, 0, 0);
layer.destroy()
map.createBlankDynamicLayer('test', tileset, 0, 0); <-- Error

Additional Information

As a workaround i manually remove name when destroy layer
Vue.delete(map.layers, map.getLayerIndexByName(layerName));

[photonstorm]

Thank you for submitting this issue. We have fixed this and the fix has been pushed to the master branch. It will be part of the next release. If you get time to build and test it for yourself we would appreciate that.