testsuite: Mark T13676 as broken on Darwin and Windows

Due to #17447.

testsuite/tests/rts/all.T

@@ -402,6 +402,7 @@ test('keep-cafs',
 test('T16514', unless(opsys('mingw32'), skip), compile_and_run, ['T16514_c.cpp -lstdc++'])
 test('test-zeroongc', extra_run_opts('-DZ'), compile_and_run, ['-debug'])
 
-test('T13676', [when(opsys('darwin'), skip), # skip on Darwin due to CI issues
-                extra_files(['T13676.hs'])],
+test('T13676',
+     [when(opsys('darwin') or opsys('mingw32'), expect_broken(17447)),
+      extra_files(['T13676.hs'])],
      ghci_script, ['T13676.script'])