Don't retain 'storable-testfile-*' after completion of testing

When run in Perl core, make test was leaving 109 files in /tmp.  The two
changes in this patch cleaned up 103 and 6 files, respectively.

Account for test failure on Windows.

The 'unlink' statement at line 284 in blead dates from 2002 and was not
altered during recent refactoring of Storable.  CI testing suggests it
is now superflous and can be removed without causing test failures on
Linux or Windows.

For: GH #22502

dist/Storable/t/lib/STTestLib.pm

@@ -22,7 +22,7 @@ sub slurp {
 sub write_and_retrieve {
     my $data = shift;
 
-    my ($fh, $filename) = tempfile('storable-testfile-XXXXX', TMPDIR => 1);
+    my ($fh, $filename) = tempfile('storable-testfile-XXXXX', TMPDIR => 1, UNLINK => 1);
     binmode $fh;
     print $fh $data or die "Can't print to '$filename': $!";
     close $fh or die "Can't close '$filename': $!";
@@ -32,7 +32,7 @@ sub write_and_retrieve {
 
 sub tempfilename {
     local $^W;
-    my (undef, $file) = tempfile('storable-testfile-XXXXX', TMPDIR => 1, UNLINK => 1, OPEN => 0);
+    my (undef, $file) = tempfile('storable-testfile-XXXXX', TMPDIR => 1, UNLINK => 1);
     return $file;
 }
 

dist/Storable/t/malice.t

@@ -280,9 +280,6 @@ test_things($contents, \&write_and_retrieve, 'file');
 my $stored = freeze \%hash;
 test_things($stored, sub { eval { thaw $_[0] } }, 'string');
 
-# Network order.
-unlink $file or die "Can't unlink '$file': $!";
-
 ok (defined nstore(\%hash, $file), "nstore() returned defined value");
 
 $expected = 20 + length ($file_magic_str) + $network_magic + $fancy;