History of JobGroup::kill 1 change

In crates/flow/src/syscall.rs, lines 415–417 on v0.5.1. 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 415,417:crates/flow/src/syscall.rs.