Enact the fourth rules update of SR2024

This makes it clear that the second challenge deadline is still available for teams who missed the first, clarifies that flags are not ever included in the size of a robot, and clarifies the "in" rule in certain situations involving stacking.

This is built from:
- srobo/rules@ee3d493
- https://github.com/srobo/rules/releases/download/SR2024.4/rulebook.html

Author: prophile