THRIFT-5600: upgrade rust toolchain to 1.61 and edition 2021
THRIFT-5606: Wrong indent for const double
Client: rs
Patch: Ommy Zhang <tdxdxoz@gmail.com>

This closes #2634
diff --git a/lib/rs/Cargo.toml b/lib/rs/Cargo.toml
index 6c862aa..1ef524e 100644
--- a/lib/rs/Cargo.toml
+++ b/lib/rs/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "thrift"
 description = "Rust bindings for the Apache Thrift RPC system"
-edition = "2018"
+edition = "2021"
 version = "0.18.0"
 license = "Apache-2.0"
 authors = ["Apache Thrift Developers <dev@thrift.apache.org>"]