chore: Release rkv version 0.18.4

Author: badboy

Cargo.toml

@@ -16,7 +16,7 @@ license = "Apache-2.0"
 name = "rkv"
 readme = "README.md"
 repository = "https://github.com/mozilla/rkv"
-version = "0.18.3"
+version = "0.18.4"
 rust-version = "1.58"
 
 [[bin]]