Update libtinyfiledialogs to 3.9.0 (#31)

See here: jdm/tinyfiledialogs-rs#35 (comment)

Author: terhechte

ps-gui/Cargo.toml

@@ -20,4 +20,4 @@ objc = "0.2.7"
 [target."cfg(not(target_arch = \"wasm32\"))".dependencies]
 ps-importer = { path = "../ps-importer" }
 shellexpand = "2.1.0"
-tinyfiledialogs = "3.0"
+tinyfiledialogs = "3.9.0"