t6132(NO_PERL): do not run the scripted `add -p`

When using the non-built-in version of `git add -p` in a `NO_PERL`
build, we expect that invocation to fail.

However, when b02fdbc80a (pathspec: correct an empty string used as a
pathspec element, 2022-05-29) added a test case to t6132 to exercise
`git add -p`, it did not add appropriate prereqs (which admittedly did
not exist back then).

Let's specify the appropriate prereqs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6132-pathspec-exclude.sh

@@ -293,7 +293,11 @@ test_expect_success 'add with all negative' '
 	test_cmp expect actual
 '
 
-test_expect_success 'add -p with all negative' '
+test_lazy_prereq ADD_I_USE_BUILTIN_OR_PERL '
+	test_have_prereq ADD_I_USE_BUILTIN || test_have_prereq PERL
+'
+
+test_expect_success ADD_I_USE_BUILTIN_OR_PERL 'add -p with all negative' '
 	H=$(git rev-parse HEAD) &&
 	git reset --hard $H &&
 	git clean -f &&