Leftover transforms from the physics tick were being flushed during idle, which was causing problems for physics interpolation.
This PR flushes the transforms at the end of the physics tick when physics interpolation is active.
Autoloaded scripts should always inherit from Node. When you run a
project that tries to autoload a script which doesn’t inherit from Node,
then Godot gives an error.
Before this change, the error said “Script does not inherit a Node”.
That error message is a little bit misleading. If a class inherits a
Node, then one of its superclasses has a Node. If a class inherits
_from_ Node, then one of its superclasses is Node. This change corrects
that mistake.
Fixes#59884.
(cherry picked from commit 1cc7e7ec33a652647d63cb32fa164eceef87c653)
