wasm_rust_binary: use edition 2021

Signed-off-by: Matt Leon <mattleon@google.com>

Author: leonm1

bazel/wasm.bzl

@@ -83,7 +83,7 @@ def wasm_rust_binary(name, tags = [], wasi = False, signing_key = [], **kwargs):
 
     rust_binary(
         name = wasm_name,
-        edition = "2024",
+        edition = "2021",
         crate_type = "cdylib",
         out_binary = True,
         tags = ["manual"],