t2024: mark a checkout -p test as requiring Perl

A recently-added test case tries to verify that the output of `checkout
-p` contains a certain piece of advice.

But if Git was built without Perl and therefore lacks support for `git
add -i`, the error output contains the hint that `-p` is not even
available instead.

Let's just skip that test case altogether if Git was built with NO_PERL.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

t/t2024-checkout-dwim.sh

@@ -76,7 +76,8 @@ test_expect_success 'checkout of branch from multiple remotes fails #1' '
 	test_branch master
 '
 
-test_expect_success 'checkout of branch from multiple remotes fails with advice' '
+test_expect_success NO_PERL \
+	'checkout of branch from multiple remotes fails with advice' '
 	git checkout -B master &&
 	test_might_fail git branch -D foo &&
 	test_must_fail git checkout foo 2>stderr &&