Treat bind-pose skinned meshes as static raytrace sources

[anirul]

Summary

• keep skinned meshes with play_animation = false on the static bind-pose raytracing path
• gate OpenGL/Vulkan skinning and raytrace buffer updates on active animation instead of bone presence alone
• add regressions covering animated fox vs bind-pose fox behavior

Verification

• built FrameOpenGLTest
• built FrameVulkanTest
• ran FrameOpenGLTest --gtest_filter='OpenGLRayTracingLevelTest.SkinnedMeshPreRenderUpdatesAggregateSceneBuffers:OpenGLRayTracingLevelTest.SkinnedMeshBindPoseDoesNotUpdateAggregateSceneBuffers:SkinnedMeshTest.LoadFoxGlbCreatesSkinnedMeshWithAnimationData'
• ran FrameVulkanTest --gtest_filter='VulkanSkinnedRayTracingParseTest.FoxAnimationChangesRaytraceTriangles:VulkanSkinnedRayTracingParseTest.FoxBindPoseDisablesDynamicRaytraceCallbacks'
• rebuilt grpcmmo_client against the updated Frame submodule