History of unpack 1 change

In crates/flow/src/checkpoint.rs, lines 110–166 on 72772aa01d6bcb6907aeeb45b887c82cdfa36a3c63fd6ea4a67c8c1ecc73d5aa. 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 110,166:crates/flow/src/checkpoint.rs.