Path tool sometimes snaps to the previous anchor positions

To reproduce:
- New document
- Draw a rectangle
- Switch to path tool
- Drag the rectangle from the centre

https://github.com/user-attachments/assets/780d4f1b-caf5-4722-92a7-3458ef5c1409

This occurs both on dev.graphite.rs and editor.graphite.rs.

Reproduce the issue in a new document by drawing a rectangle, switching to the path tool, and dragging from its centre in either listed editor. Trace how the path tool handles anchor positions during that drag; done means the rectangle no longer snaps to its previous anchor positions.

Written by the indexing model from the issue text.