Replace deprecated rust_repositories

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index fe453cd..86ecc81 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -246,9 +246,11 @@
 
 rust_repos()
 
-load("@rules_rust//rust:repositories.bzl", "rust_repositories")
+load("@rules_rust//rust:repositories.bzl", "rules_rust_dependencies", "rust_register_toolchains")
 
-rust_repositories()
+rules_rust_dependencies()
+
+rust_register_toolchains(edition="2021")
 
 #
 # Scala