History of Pool::keep 2 changes

In crates/flow/src/cache.rs, lines 146–163 on 97b9cfeb7d66203e584c00be7499611bdf4abbfd44e2610f739a25c72a2d9076. 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 146,163:crates/flow/src/cache.rs.