Skip the command#Run test for fixers on Windows

test/fix/test_ale_fix.vader

@@ -816,9 +816,14 @@ Execute(ALEFix should apply autocmds):
   AssertEqual g:post_success, 1
 
 Execute(ALEFix should support ale#command#Run):
+  if has('win32')
+    " Just skip this test on Windows, we can't run it.
+    call setline(1, ['a', 'b', 'c', 'd'])
+  else
     let g:ale_fixers.testft = ['CatLineDeferred']
     ALEFix
     call ale#test#FlushJobs()
+  endif
 
 Expect(The extra line should be added):
   a