Crash when table_bonus loot condition has empty chances list

Summary
table_bonus loot condition does not validate that chances list has an entry. When that list is empty, testing the loot condition triggers an error or (in case of an explosion) a crash.

Steps to Reproduce

1. Add the attached data pack. (Works with both 1.20.4 and 24w11a.)
2. Explode a stone block with TNT.

Expected Result
The game does not crash.

Actual Result
The game crashes.