History of Pool::keep 2 changes

In crates/flow/src/cache.rs, lines 146–163 on 85998eeba77ec6507b58059a90d79840e98c0fee05f573c53e0af46406ebf78b. 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.