rust: update fs4 to 0.9

Summary: Needed for new version of `pore`.

Reviewed By: dtolnay

Differential Revision: D73431196

fbshipit-source-id: 46ddbf0b2180278cfea0a2664ca9d4c4032c82e1

Author: jeremy-meta

shim/third-party/rust/Cargo.toml

@@ -89,7 +89,7 @@ faccess = "0.2.3"
 fancy-regex = "0.10.0"
 flate2 = "1.0.22"
 fnv = "1.0.7"
-fs4 = { version = "0.6", features = ["sync"] }
+fs4 = { version = "0.9.1", features = ["sync"] }
 futures = { version = "0.3.28", features = ["async-await", "compat"] }
 futures-intrusive = "0.4"
 fxhash = "0.2.1"