Create Train Physics Reloaded 0.2.0-beta.4

Create Train Physics Reloaded 0.2.0-beta.4

Fix

• The automatic handbrake applies gradual service braking when manual control
  ends while a train is moving. Stopped trains remain held on slopes.

Verification

• A clean build and runtime mixin-load smoke test passed on Minecraft 1.21.1,
  NeoForge 21.1.217, and Create 6.0.8.
• 88 regression tests passed.
• Release JAR SHA-256:
  6acfb5cbc777e43d304ec7e50a61dd08dcedec5a928af910f48ac69d2a99f3bc.