This release features several new vendor extensions, as well as some
small improvements and fixes to the software.

-   Registry
    -   Change: Allow structs that can extend multiple other structs in
        the RelaxNG schema, as already permitted by the Vulkan schema.
        (internal MR 2869)
    -   New vendor extension: XR_HTC_body_tracking (internal MR 2549)
    -   New vendor extension: XR_ML_spatial_anchors (internal MR 2803)
    -   New vendor extension: XR_ML_spatial_anchors_storage (internal MR
        2804)
    -   New vendor extension: XR_ML_system_notifications (internal MR
        2946)
    -   New vendor extension: XR_ML_world_mesh_detection (internal MR
        2950)
    -   New vendor extension:
        XR_ML_view_configuration_depth_range_change (internal MR 3036)
-   SDK
    -   Fix: Do not enforce overly-strict requirements on structs using
        *BaseHeader types in the code generation scripts, fixing a
        build-time warning for the layers. (internal MR 3434)
    -   Improvement: Migrate CMake build system away from using
        find_package(PythonInterpreter), deprecated since CMake 3.12.
        Use find_package(Python3 COMPONENTS Interpreter) instead.
        (OpenXR-SDK-Source PR 486, internal MR 3472)
    -   Validation layer: Improvement: Clean up generate_vuid_database
        script, used to analyze the validation layer. (internal MR 2895)
    -   ci: Remove now-redundant gradle-wrapper-validation job from
        GitHub Actions (OpenXR-SDK-Source PR 500)
    -   ci: Add GitHub Action for macOS building (OpenXR-SDK-Source PR
        501)
    -   doc: Add command to build OpenXR targets on macOS
        (OpenXR-SDK-Source PR 501)
    -   hello_xr: Addition: Log Vulkan extensions requested by runtime
        and by app, visible when running with --verbose.
        (OpenXR-SDK-Source PR 403)

GitOrigin-RevId: 4980d84000eb8b4d88c4fb29877c695526c94ca8