### Godot version

4.1.1

### System information

Meta Quest 2 - GLES3

### Issue description

When writing VR applications on Godot 4 using gl_compatibility, skeleton-driven meshes like hands are often rendered corrupted, or sometimes update slowly.

### Steps to reproduce

The godot-xr-tools demo projects have these issues in the climbing/gliding and pointer-demo scenes if the project is switched to gl_compatibility mode and run on a mobile VR headset.

### Minimal reproduction project

The godot-xr-tools demo project has been the testing project for this issue.
float *w = decompressed.ptrw();
		const float *r = ret.ptr();
		for (int i = 0; i < multimesh->instances; i++) {
			{
				float *newptr = w + i * new_stride;
				const float *oldptr = r + i * multimesh->stride_cache;
				float vals[8] = { oldptr[0], oldptr[1], oldptr[2], oldptr[3], oldptr[4], oldptr[5], oldptr[6], oldptr[7] };
				memcpy(newptr, vals, 8 * 4);
			}
			if (multimesh->xform_format == RS::MULTIMESH_TRANSFORM_3D) {
				float *newptr = w + i * new_stride + 8;
				const float *oldptr = r + i * multimesh->stride_cache + 8;
				float vals[8] = { oldptr[0], oldptr[1], oldptr[2], oldptr[3] };
				memcpy(newptr, vals, 4 * 4);
			}
			if (multimesh->uses_colors) {
				float *newptr = w + i * new_stride + (multimesh->xform_format == RS::MULTIMESH_TRANSFORM_2D ? 8 : 12);
				const float *oldptr = r + i * multimesh->stride_cache + multimesh->color_offset_cache;
				uint16_t raw_data[4];
				memcpy(raw_data, oldptr, 2 * 4);
				newptr[0] = Math::half_to_float(raw_data[0]);
				newptr[1] = Math::half_to_float(raw_data[1]);
				newptr[2] = Math::half_to_float(raw_data[2]);
				newptr[3] = Math::half_to_float(raw_data[3]);
			}
			if (multimesh->uses_custom_data) {
				float *newptr = w + i * new_stride + (multimesh->xform_format == RS::MULTIMESH_TRANSFORM_2D ? 8 : 12) + (multimesh->uses_colors ? 4 : 0);
				const float *oldptr = r + i * multimesh->stride_cache + multimesh->custom_data_offset_cache;
				uint16_t raw_data[4];
				memcpy(raw_data, oldptr, 2 * 4);