Remove rust-toolchain file

[xtqqczze]

Cargo versions bundled with Rust 1.56.0 and later support rust-version in Cargo.toml. So a rust-toolchain file shouldn't be necessary.

[chris-zen]

Hi @xtqqczze , thanks for taking care of those details. I'll be giving a push to this project during the weekend. So I'll work on fixing all that kind of things. Let me know in this thread if there are other concerns to you.

Current focus:

• Update CI and rust version (perhaps edition)
• Easy things to fix from the issues list
• Update dependencies

I'm also open to do a major release with important refactors:

• Have proper Errors instead of OSStatus
• Have fallible API for packets/events

Looking forward for your feedback.

[chris-zen]

Addressed in #63

[xtqqczze]

There's a few lints that could be fixed:

$ cargo +nightly clippy --all-targets --workspace --message-format=json --quiet -- -W clippy::pedantic    | jq -r '.message.code.code | select(. != null and startswith("clippy::"))'    | sort | uniq -c | sort -h -r

 146 clippy::must_use_candidate
  75 clippy::doc_markdown
  54 clippy::ptr_as_ptr
  54 clippy::missing_errors_doc
  41 clippy::uninlined_format_args
  24 clippy::cast_possible_wrap
  20 clippy::cast_sign_loss
  12 clippy::semicolon_if_nothing_returned
  12 clippy::cast_ptr_alignment
  10 clippy::explicit_deref_methods
   8 clippy::single_match_else
   8 clippy::match_same_arms
   7 clippy::borrow_as_ptr
   6 clippy::ignored_unit_patterns
   5 clippy::unreadable_literal
   5 clippy::ptr_cast_constness
   4 clippy::cast_possible_truncation
   3 clippy::redundant_closure_for_method_calls
   2 clippy::unnecessary_semicolon
   2 clippy::return_self_not_must_use
   2 clippy::manual_string_new
   2 clippy::explicit_iter_loop
   2 clippy::elidable_lifetime_names
   2 clippy::duration_suboptimal_units
   2 clippy::double_ended_iterator_last
   2 clippy::bool_to_int_with_if
   1 clippy::needless_pass_by_value
   1 clippy::large_stack_arrays

Any "ptr" lints especially.