Req: Switch to Rust stable channel

[xiota]

My intention was to make minimal changes to the AUR package, but I found myself on a slippery slope. The package is now able to build 113a590, which is the last commit that built for Linux on check-in.

A problem I encountered is previously buildable commits could no longer compile. To prevent changes in Rust itself from randomly breaking this program, you may wish to consider switching to the stable channel.

[RealRTTV]

these are the nightly features im using right now:

    allocator_api,
	assert_matches,
	associated_type_defaults,
	cold_path,
	duration_millis_float,
	if_let_guard,
	inherent_associated_types,
	let_chains,
	likely_unlikely,
	maybe_uninit_array_assume_init,
	never_type,
	panic_update_hook,
	ptr_as_ref_unchecked,
	try_trait_v2,
	try_with_capacity,
	vec_push_within_capacity,
	array_chunks,
	box_patterns,
	iter_array_chunks,
	iter_next_chunk,
	stmt_expr_attributes

it would be really annoying and hard to replace all of these

[xiota]

I don't know the specific process, but in principle, nightly features should eventually move to stable. As long as new features aren't added to the list, might be possible to switch to stable someday without much effort.