Mark Terminate package test as flaky wrt #11087

Author: hasufell

cabal-testsuite/PackageTests/NewBuild/CmdRun/Terminate/cabal.test.hs

@@ -19,7 +19,7 @@ without forking in the future.)
 main :: IO ()
 main = do
   skipIfWindows "depends on `unix`"
-  cabalTest $ do
+  cabalTest $ flakyIfCI 8416 $ do
     -- timestamped logging to aid with #8416
     let logIO msg = do
           ts <- Time.getCurrentTime