fixup! refactor(cli): rewrite rustup (toolchain|update|(un)?install) with clap-derive

Author: rami3l

tests/suite/cli-ui/rustup/rustup_toolchain_cmd_install_cmd_help_flag_stdout.toml

@@ -13,8 +13,8 @@ Arguments:
 Options:
       --profile <PROFILE>         [possible values: minimal, default, complete]
   -c, --component <COMPONENT>...  Add specific components on installation
-  -t, --target <targets>...       Add specific targets on installation
-      --no-self-update            Don't perform self update when running the`rustup toolchain
+  -t, --target <TARGET>...        Add specific targets on installation
+      --no-self-update            Don't perform self update when running the `rustup toolchain
                                   install` command
       --force                     Force an update, even if some components are missing
       --allow-downgrade           Allow rustup to downgrade the toolchain to satisfy your component