tests: remove most uses of test_i18ncmp

As a follow-up to d162b25f956 (tests: remove support for
GIT_TEST_GETTEXT_POISON, 2021-01-20) remove most uses of test_i18ncmp
via a simple s/test_i18ncmp/test_cmp/g search-replacement.

I'm leaving t6300-for-each-ref.sh out due to a conflict with in-flight
changes between "master" and "seen", as well as the prerequisite
itself due to other changes between "master" and "next/seen" which add
new test_i18ncmp uses.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t3201-branch-contains.sh b/t/t3201-branch-contains.sh
index 578b5f4..349a810 100755
--- a/t/t3201-branch-contains.sh
+++ b/t/t3201-branch-contains.sh
@@ -264,7 +264,7 @@
 	* topic $(git rev-parse --short topic ) [ahead 1] foo
 	  zzz   $(git rev-parse --short zzz   ) second on main
 	EOF
-	test_i18ncmp expect actual
+	test_cmp expect actual
 '
 
 test_done