Scenario: up-to-date
A splice freshly cloned and never touched again on either side.
Output
setup.bash builds this state:
$ build_scenario scenario_up_to_date
Nothing to do on either side:
$ git splice status
On branch main
up to date vendor/a
$ git splice push vendor/a
ok vendor/a: nothing to push
$ git splice pull vendor/a
ok vendor/a fetched
ok vendor/a: nothing to pull