OM2-QA tests: remove _test_sync_userscript..._

[anton-seaice]

After ACCESS-OM2 2026.02.000 deployment with ACCESS-NRI/cice5#72, the sync userscript is not required:

model-config-tests/src/model_config_tests/config_tests/qa/test_access_om2_config.py

Lines 129 to 140 in 31685c1

	def test_sync_userscript_ice_concatenation(self, config):
	# This script runs in the sync pbs job before syncing output to a
	# remote location
	script = "/g/data/vk83/apps/om2-scripts/concatenate_ice/concat_ice_daily.sh"
	assert (
	"userscripts" in config
	and "sync" in config["userscripts"]
	and config["userscripts"]["sync"] == script
	), (
	"Expect sync userscript set to ice-concatenation script."
	+ f"\nuserscript:\n sync: {script}"
	)

We could only run that test depending on the version of ACCESS-OM2, or delete the test ?

[anton-seaice]

My feeling is it's safe to delete the test, as I don't think we need backward compatibility for these QA tests ? (folks can use an old version in the case of say, hotfixing an old config)