tests: remove all uses of test_i18cmp
Finish the removal I started in
1108cea7f8e (tests: remove most uses
of test_i18ncmp, 2021-02-11). At that time the function wasn't removed
due to disruption with in-flight changes, remove the occurrences that
have landed since then.
As of writing this there are no test_i18ncmp uses between "master" and
"seen", so let's also remove the function to finally put it to rest.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>