Custom python API layer is not working on linux.

[cmbruns]

NOTE: this refers to development code that is not released yet.

• our layer XR_APILAYER_PYOPENXR_Example_Layer appears in xr.enumerate_api_layer_properties()
  • so the loader is finding the temporary json folder
• function insertXrApiLayer() is being called from python
• but xrNegotiateLoaderApiLayerInterface() is not being called from the loader
• loader log message says "Error [GENERAL | xrCreateInstance | OpenXR-Loader] : ApiLayerInterface::LoadApiLayers - failed to find layer XR_APILAYER_PYOPENXR_Example_Layer"
• message probably comes from ApiLayerInterface::LoadApiLayers()
• maybe look at AddEnvironmentApiLayers()