refactor: Refactor pipx update function for quiet execution

[crrlcx]

• Updated the run_pipx_update function in the generic.rs file to execute the pipx upgrade-all command in quiet mode, enhancing the performance by reducing console output.

Standards checklist:

• The PR title is descriptive.
• I have read CONTRIBUTING.md
• The code compiles (cargo build)
• The code passes rustfmt (cargo fmt)
• The code passes clippy (cargo clippy)
• The code passes tests (cargo test)
• Optional: I have tested the code myself

For new steps

• Optional: Topgrade skips this step where needed
• Optional: The --dry-run option works with this step
• Optional: The --yes option works with this step if it is supported by
  the underlying command

If you developed a feature or a bug fix for someone else and you do not have the
means to test it, please tag this person here.

[SteveLauC]

I tried this command on my host, the --quiet option does not seem to exist:

$ pipx --version
1.1.0

$ pipx upgrade-all --quiet
usage: pipx [-h] [--version]
            {install,inject,upgrade,upgrade-all,uninstall,uninstall-all,reinstall,reinstall-all,list,run,runpip,ensurepath,environment,completions}
            ...
pipx: error: unrecognized arguments: --quiet