Ignore buggy clip gm on Mac 10.9

expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json

Index: expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json
diff --git a/expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json b/expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json
index ea7810300010f258889df78512977652955c1bba..1107351a6592f205778971f3b501bf5e33c3b967 100644
--- a/expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json
+++ b/expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json
@@ -16715,6 +16715,7 @@
           14852444518787952875
         ]
       ], 
+      "ignore-failure": true, 
       "reviewed-by-human": true
     }, 
     "simpleaaclip_path_pdf-mac.png": {
@@ -19343,4 +19344,4 @@
       "reviewed-by-human": true
     }
   }
-}
+}