Fix help string for "--charset" option of "cargo tree"

[BinderDavid]

The help text for the cargo tree subcommand currently is:

> cargo --version
cargo 1.67.1 (8ecd4f20a 2023-01-10)
> cargo tree --help
Display a tree visualization of a dependency graph

Usage: cargo tree [OPTIONS]

Options:
  -q, --quiet                 Do not print cargo log messages
      --manifest-path <PATH>  Path to Cargo.toml
  -p, --package [<SPEC>]      Package to be used as the root of the tree
  -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
      --workspace             Display the tree for all packages in the workspace
      --exclude <SPEC>        Exclude specific workspace members
      --color <WHEN>          Coloring: auto, always, never
      --frozen                Require Cargo.lock and cache are up to date
  -F, --features <FEATURES>   Space or comma separated list of features to activate
      --locked                Require Cargo.lock is up to date
      --all-features          Activate all available features
      --offline               Run without accessing the network
      --config <KEY=VALUE>    Override a configuration value
      --no-default-features   Do not activate the `default` feature
      --target <TRIPLE>       Filter dependencies matching the given target-triple (default host platform). Pass `all` to include all targets.
  -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
  -e, --edges <KINDS>         The kinds of dependencies to display (features, normal, build, dev, all, no-normal, no-build, no-dev, no-proc-macro)
  -i, --invert [<SPEC>]       Invert the tree direction and focus on the given package
      --prune <SPEC>          Prune the given package from the display of the dependency tree
      --depth <DEPTH>         Maximum display depth of the dependency tree
      --prefix <PREFIX>       Change the prefix (indentation) of how each entry is displayed [default: indent] [possible values: depth, indent, none]
      --no-dedupe             Do not de-duplicate (repeats all shared dependencies)
  -d, --duplicates            Show only dependencies which come in multiple versions (implies -i)
      --charset <CHARSET>     Character set to use in output: utf8, ascii [default: utf8] [possible values: utf8, ascii]
  -f, --format <FORMAT>       Format string used for printing dependencies [default: {p}]
  -h, --help                  Print help information

Note that for the --charset option, the information about available encodings is duplicated. This PR removes the duplication.

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @epage (or someone else) soon.

Please see the contribution instructions for more information.

[weihanglo]

Nice catch. Thanks!

[weihanglo]

@bors r+

[bors]

📌 Commit 80836cf has been approved by weihanglo

It is now in the queue for this repository.

[bors]

⌛ Testing commit 80836cf with merge e472ccc...

[bors]

☀️ Test successful - checks-actions
Approved by: weihanglo
Pushing e472ccc to master...