omit branch names from output

[zeke]

Hey @wei 👋🏼

The current behavior of this Action is to output every branch name in the logs:

echo "Fetching tmp_upstream"
git fetch tmp_upstream

For projects that have lots of branches, this produces a lot of output.

My request is that we add the --quiet flag to git fetch tmp_upstream --quiet, or add support for a parameter like fetch_quietly that can be specified in the workflow file and passed to the Action as an argument.