Update rust in run_fuzz.sh script

One of the crates (clap) used by cargo-fuzz needs rustc 1.64.0 or newer
and the docker image uses 1.62.1 currently. This patch updates the
rust version.

Signed-off-by: Gowtham Suresh Kumar <gowtham.sureshkumar@arm.com>

Author: gowthamsk-arm

fuzz/run_fuzz.sh

@@ -5,6 +5,9 @@
 
 set -ex
 
+# Use the newest version of the Rust toolchain
+rustup update
+
 # The clean up procedure is called when the script finished or is interrupted
 cleanup () {
     # Stop tpm_server if running