chore: upgrade memmap2 0.5.7 -> 0.9.4 (#248)

Signed-off-by: boxdot <d@zerovolt.org>

Author: boxdot

flatdata-rs/lib/Cargo.toml

@@ -12,7 +12,7 @@ edition = "2018"
 
 [dependencies]
 diff = "0.1.11"
-memmap2 = "0.5.7"
+memmap2 = "0.9.4"
 tar = { version = "0.4.38", optional = true }
 walkdir = "2.2.9"