wgpu: Potential memory leak

Description After moving to wgpu, few people testing the branch started to complain about the game getting slower and slower with the time. We started to dig in into the problem and we found out that

_ZN15veloren_voxygen6render8renderer8Renderer23create_consts_ui_locals17h3c8b311cd8cd64b0E which goes to _ZN4wgpu6Device17create_bind_group17hd8df2faa8758b09eE looked like it was leaking something internally in wgpu when using vulkan backend.

AFAIK it doesn’t happen on master which still uses old backend.

Repro steps https://gitlab.com/veloren/veloren/-/tree/capucho/wgpu

Extra materials

Platform Information about your OS, version of wgpu, your tech stack, etc. Windows 10 WGPU 0.5.4 vulkan backend