We use Perl due to two different reasons in t5703:
- To filter advertised capabilities.
- To set up a CGI script with HTTPD.
Refactor the first category to use `test_grep` instead. Refactoring the
second category would be a bit more involved, so instead we add the
PERL_TEST_HELPERS prerequisite to those individual tests now.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>