third party: Upgrade syn to 2.0.101

Summary: Pick up dtolnay/syn#1861

Reviewed By: dtolnay

Differential Revision: D73726005

fbshipit-source-id: aca81e034ceb0feb522d23a334aad4761c04a6e4

Author: JakobDegen

shim/third-party/rust/Cargo.toml

@@ -193,7 +193,7 @@ static_assertions = "1.1.0"
 strsim = "0.10.0"
 structopt = "0.3.23"
 strum = { version = "0.26.2", features = ["derive", "strum_macros"] }
-syn = { version = "2", features = ["extra-traits", "full", "visit"] }
+syn = { version = "2.0.101", features = ["extra-traits", "full", "visit"] }
 syn1 = { package = "syn", version = "1.0.109", features = ["extra-traits", "fold", "full", "visit", "visit-mut"] }
 synstructure = "0.12"
 sync_wrapper = "0.1.0"