tests/executable.rs: avoid the new test on Windows

I've tried a few different things but can't actually figure out how to
get the backslashes to come through correctly right now. The bug in
question shouldn't have any interesting platform dependence so just skip
the test on Windows.

Author: pkgw

tests/executable.rs

@@ -420,7 +420,12 @@ a
 ///
 /// We need to create a separate temporary directory to see if the abspath input
 /// gets messed up.
+///
+/// Backslashes in Windows paths mess up our naive test. I can't figure out how
+/// to get them to work here (admittedly, not trying too hard) so I'm just
+/// skipping this test on that platform.
 #[test]
+#[cfg(not(windows))]
 fn biber_issue_844() {
     let temp_source = setup_and_copy_files(&[]);
     let mut bibpath = std::fs::canonicalize(temp_source.path()).unwrap();