Deferred Rendering example broken on WebGL2

[DGriffin91]

Bevy version 64faadb

The deferred rendering example is broken on WebGL2.

The issue was introduced at 44928e0 with #8015

panicked at 'wgpu error: Validation Error

Caused by:
    In Device::create_render_pipeline
      note: label = `pbr_opaque_mesh_pipeline`
    Internal error in ShaderStages(FRAGMENT) shader: WGSL `textureLoad` from depth textures is not supported in GLSL