[vm/transferable] SkipSlow long-running transferable test on sim* pla…

…tforms

Change-Id: If829ee2d141abda2551945da07e03e4abdc3cf73
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/105341
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>

runtime/tests/vm/vm.status

@@ -178,6 +178,7 @@ cc/ScriptSnapshotsUpdateSubclasses: Fail, Crash, OK # Script snapshots not suppo
 
 [ ($compiler == dartk || $compiler == dartkb) && ($arch == simarm || $arch == simarm64 || $arch == simdbc || $arch == simdbc64) ]
 dart/appjit*: SkipSlow # DFE too slow
+dart/issue_31959_31960_test: SkipSlow
 
 # Enabling of dartk for sim{arm,arm64,dbc64} revelaed these test failures, which
 # are to be triaged.  Isolate tests are skipped on purpose due to the usage of