History of sigv4 1 change

In crates/hub/src/backups.rs, lines 457–482 on 1062a0f8e985bb8c65ab90ccae6309f38730152b13ca9e9c579d6f5751053161. 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 457,482:crates/hub/src/backups.rs.