Setting the `progress` option to false in the `with` section of the
workflow step will cause git fetch to run without `--progress`.
The motivation is to be able to suppress the noisy progress status
output which adds many hundreds of "remote: Counting objects: 85%
(386/453)" and similar lines in the workflow log.
This should be sufficient to resolve#894 and its older friends,
though the solution is different to the one proposed there because
it doesn't use the --quiet flag. IIUC git doesn't show the progress
status by default since the output is not a terminal, so that's why
removing the --progress option is all that's needed.
* Adding the ability to specify the GitHub Server URL and allowing for it to differ from the Actions workflow host
* Adding tests for injecting the GitHub URL
* Addressing code review comments for PR #922
