History of scheduler 2 changes

In crates/hub/src/flow.rs, lines 1678–1692 on 73ef9f7671328214d75c86253d0e1094580d7cace048c6d44716d68728d58fde. 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 1678,1692:crates/hub/src/flow.rs.