Add a dependency graph relation Force Object Animation → Scene Rigid
Body World Rebuild. This ensures that the rigid body world is rebuilt
when a force object is re-tagged for animation updates.
The extra relation doesn't add any new calculations when the animation
is running, as the Time Source node already had a relation to the
scene's `RIGIDBODY_REBUILD` node.
The relation is created directly to the `RIGIDBODY_REBUILD` Operation. I
would have liked to target the containing Component instead. However,
that has the `RIGIDBODY_SIM` operation as entry node, which isn't enough
to actually fix T80121.
Reviewers: Sergey
Differential Revision: https://developer.blender.org/T80121
48a0c931ee