downgrade redb to make it work with edition 2021

Author: rklaehn

Cargo.lock

@@ -13,7 +13,7 @@ quinn = { package = "iroh-quinn", version = "0.14.0" }
 n0-future = "0.1.2"
 n0-snafu = "0.2.0"
 range-collections = { version = "0.4.6", features = ["serde"] }
-redb = "2.4.0"
+redb = { version = "=2.4" }
 smallvec = { version = "1", features = ["serde", "const_new"] }
 snafu = "0.8.5"
 tokio = { version = "1.43.0", features = ["full"] }