History of JobGroup::drop 1 change

In crates/flow/src/syscall.rs, lines 458–467 on da72c3b192c3926c37e2db6e386b8eb2c95762e7108a730dac7e8a2d7f4e078d. 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.