simplify_static_dir/t/sha1collision-non-linkage.t

#!perl
use strict;
use warnings;

use Test::Simple
    tests => 3;

use TestFunctions;

my $tarball_dir = prep_tar();
my $test_dir = "$tarball_dir/t/sha1-collision";
my @files = (
    "$test_dir/shattered-1.pdf",
    "$test_dir/shattered-2.pdf",
);

# Smoke test
ok !are_hardlinked(@files), 'not hardlinked before we start';
run_script($test_dir);
ok file_exists(@files), 'files were not accidentally deleted';
ok !are_hardlinked(@files), 'files with the same SHA-1 hash did not get hardlinked';