Physics interpolation is not implemented for 3D

[rburing]

Tested versions

Reproducible in: 4.0-alpha1 - 4.3.dev5
Not reproducible in: 3.5-beta2 - 3.6-beta4

System information

Godot v4.3.dev (99ff024) - Ubuntu 22.04.4 LTS 22.04 - X11 - GLES3 (Compatibility) - NVIDIA GeForce RTX 2060 with Max-Q Design - AMD Ryzen 9 4900HS with Radeon Graphics (16 Threads)

Issue description

The project setting physics/common/physics_interpolation and the node property physics_interpolation_mode have no effect on 3D nodes such as physics bodies moved in _physics_process.

I could use an addon like https://github.com/lawnjelly/smoothing-addon/tree/4.x, but I would prefer a built-in solution.

Steps to reproduce

1. Run the attached MRP which has its physics tick rate set to 20 ticks per second and physics interpolation enabled.
2. Notice the 3D scene does not look smooth.

Minimal reproduction project (MRP)

physics-interpolation-3d-test.zip

• Production edit: Related to Add physics step interpolation in 3D (implemented in 2D since 4.3) godot-proposals#2753.