History of sigv4 1 change

In crates/hub/src/backups.rs, lines 457–482 on 8501fd5815b9e83cd465032461acf282f4538f115450cef2e0272e12284fd83b. 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.