Fix: Unable to create Cubemap Arrays using GPU Wrapper

When using `Texture.ensure_cube_array` the resulting texture wasn't actually
layered (array) and when used resulted into incorrect behavior.

Until now this function isn't used, but will be in when Eevee-next
world reflective light PR lands #108149 .

Pull Request: https://projects.blender.org/blender/blender/pulls/109497

source/blender/draw/intern/DRW_gpu_wrapper.hh

@@ -691,7 +691,7 @@ class Texture : NonCopyable {
                          float *data = nullptr,
                          int mip_len = 1)
   {
-    return ensure_impl(extent, extent, layers, mip_len, format, usage, data, false, true);
+    return ensure_impl(extent, extent, layers, mip_len, format, usage, data, true, true);
   }
 
   /**