jammy-amd64-tf-a-build-next: Support Nightly Rust

Also install the Rust nightly toolchain to allow testing of unstable
features like BTI and PAC.

Change-Id: Ibda04f4d75de5688cd116c71aff8d1386210929d
Signed-off-by: Matthew Maurer <mmaurer@google.com>
1 file changed