OpenXR-SDK Dependency

Notes about maintaining the OpenXR-SDK library dependency.

Updating to new Version

Repository: https://github.com/KhronosGroup/OpenXR-SDK
Note: Use the OpenXR-SDK repository, NOT the OpenXR-SDK-Source one!

• build_files/build_environment/cmake/xr_openxr.cmake: may require version number changes
• build_files/build_environment/cmake/versions.cmake: update XR_OPENXR_SDK_VERSION and XR_OPENXR_SDK_HASH (MD5 of .tar.gz)
• build_files/build_environment/install_deps.sh: update XR_OPENXR_VERSION and XR_OPENXR_REPO_UID (commit hash)
• build_files/cmake/platform_win32.cmake: may require version number changes

Remember to always check the specification's change log for compatibility breaking changes.