rust: remove allow(unaligned_references) & (default_alloc_handler) as they are no longer allowed

Bug: 288144149
Test: build.py
Change-Id: I981371404d8085495f935bc719b17439d054de4a
diff --git a/memref-test/rust/memref_test.rs b/memref-test/rust/memref_test.rs
index c7bfd94..afe0560 100644
--- a/memref-test/rust/memref_test.rs
+++ b/memref-test/rust/memref_test.rs
@@ -7,7 +7,6 @@
 #[allow(bad_style)]
 #[allow(dead_code)] // Needed because not all variants of the `lender_command` enum are used.
 #[allow(deref_nullptr)] // https://github.com/rust-lang/rust-bindgen/issues/1651
-#[allow(unaligned_references)] // https://github.com/rust-lang/rust/issues/82523
 mod sys {
     include!(env!("BINDGEN_INC_FILE"));
 }
diff --git a/rust_no_std/main.rs b/rust_no_std/main.rs
index 5b08c33..13a76e7 100644
--- a/rust_no_std/main.rs
+++ b/rust_no_std/main.rs
@@ -22,7 +22,6 @@
 
 #![no_std]
 #![feature(start)]
-#![feature(default_alloc_error_handler)]
 
 use core::panic::PanicInfo;
 use trusty_std::alloc::{FallibleVec, Vec};