Update dependencies and remove unsafe code

[maybeetree]

Dear maintainer,

This pull requests updates all dependencies to latest version,
thereby removing (indirect) dependencies on unmaintained packages.
Additionally, it also replaces the unsafe is_atty function with Rust's native is_terminal().
Project version is bumped to 2.0.1.

cargo audit report before this pull request:

    Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
      Loaded 881 security advisories (from /root/.cargo/advisory-db)
    Updating crates.io index
       Found 'cargo auditable' data in /usr/bin/vsv (38 dependencies)
Crate:     atty
Version:   0.2.14
Warning:   unmaintained
Title:     `atty` is unmaintained
Date:      2024-09-25
ID:        RUSTSEC-2024-0375
URL:       https://rustsec.org/advisories/RUSTSEC-2024-0375
Dependency tree:
atty 0.2.14
└── clap 3.2.7
    └── vsv 2.0.0

Crate:     proc-macro-error
Version:   1.0.4
Warning:   unmaintained
Title:     proc-macro-error is unmaintained
Date:      2024-09-01
ID:        RUSTSEC-2024-0370
URL:       https://rustsec.org/advisories/RUSTSEC-2024-0370
Dependency tree:
proc-macro-error 1.0.4
└── clap_derive 3.2.7
    └── clap 3.2.7
        └── vsv 2.0.0

Crate:     crossbeam-channel
Version:   0.5.5
Warning:   yanked
Dependency tree:
crossbeam-channel 0.5.5
└── rayon-core 1.9.3
    └── rayon 1.5.3
        └── vsv 2.0.0

warning: 3 allowed warnings found in /usr/bin/vsv

cargo audit report after this pull request:

    Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
      Loaded 881 security advisories (from /root/.cargo/advisory-db)
    Updating crates.io index
       Found 'cargo auditable' data in target/debug/vsv (30 dependencies)

Thank you for taking the time to review my pull request.