upgrades dashmap to v6.0

Author: Byron

gix-tempfile/Cargo.toml

@@ -31,7 +31,7 @@ test = true
 [dependencies]
 gix-fs = { version = "^0.11.2", path = "../gix-fs" }
 parking_lot = "0.12.1"
-dashmap = { version = "5.1.0", optional = true }
+dashmap = { version = "6.0.1", optional = true }
 once_cell = { version = "1.8.0", default-features = false, features = ["race", "std"] }
 tempfile = "3.10.0"