trivial: cargo update and fix lints

Update Rust and dependencies and fix resulting lints.

Signed-off-by: Dan Cross <cross@gajendra.net>

monitor/src/cons.rs

@@ -7,7 +7,7 @@
 
 use uart::arch::Uart;
 
-pub(crate) type Error = core::convert::Infallible;
+pub(crate) type Error = ();
 pub(crate) type Result<T> = core::result::Result<T, Error>;
 
 fn readline<'a>(uart: &mut Uart, prompt: &str, line: &'a mut [u8]) -> Result<&'a [u8]> {

theon/src/allocator.rs

@@ -524,6 +524,6 @@ mod global {
         static mut ALLOC: QuickFit = QuickFit::new(BumpAlloc::new(unsafe {
             Block::new_from_raw_parts(ptr::addr_of_mut!(HEAP).cast(), mem::size_of::<GlobalHeap>())
         }));
-        unsafe { ptr::addr_of_mut!(ALLOC) }
+        ptr::addr_of_mut!(ALLOC)
     }));
 }

theon/src/main.rs

@@ -6,7 +6,6 @@
 // https://opensource.org/licenses/MIT.
 
 #![feature(allocator_api)]
-#![feature(const_mut_refs)]
 #![feature(exposed_provenance)]
 #![feature(naked_functions)]
 #![feature(ptr_sub_ptr)]

x86_64/src/lib.rs

@@ -43,7 +43,6 @@
 //! page in some address space.  The page may or may
 //! not be mapped.
 
-#![feature(asm_const)]
 #![feature(assert_matches)]
 #![feature(fn_align)]
 #![feature(naked_functions)]