Bump syn to 1.0.81 (#707)

* Bump syn to 1.0.81

* Make formatting check happy

pallets/dmp-queue/src/lib.rs

@@ -307,7 +307,7 @@ pub mod pallet {
 									id, remaining, required,
 								));
 							}
-						}
+						},
 					}
 				}
 				// Cannot be an `else` here since the `maybe_enqueue_page` may have changed.

pallets/parachain-system/proc-macro/Cargo.toml

@@ -9,7 +9,7 @@ description = "Proc macros provided by the parachain-system pallet"
 proc-macro = true
 
 [dependencies]
-syn = "1.0.73"
+syn = "1.0.81"
 proc-macro2 = "1.0.27"
 quote = "1.0.9"
 proc-macro-crate = "1.0.0"