History of JobGroup::drop 1 change

In crates/flow/src/syscall.rs, lines 458–467 on 0f2b8eca36b8dd185236825d2687c1dbc009590c2d5a51ade3da9b94b4ed5195. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 458,467:crates/flow/src/syscall.rs.