[gardening] Skip recently added shared_* test on simarm

Fix failures https://ci.chromium.org/ui/p/dart/builders/ci.sandbox/vm-linux-release-simarm/5800/overview, https://ci.chromium.org/p/dart/builders/ci.sandbox/vm-aot-linux-release-simarm_x64/5709

Followup to 4faed73, feabbd9

TEST=ci

Change-Id: Ia7ac4411a53cc5c2fd963d55dbcbeb584e9910e2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442704
Reviewed-by: Ryan Macnak <[email protected]>
Commit-Queue: Alexander Aprelev <[email protected]>

Author: aam

runtime/tests/vm/vm.status

@@ -243,6 +243,8 @@ dart/regress_41971_test: SkipByDesign # https://dartbug.com/37299 dart:ffi is no
 dart/regress_b_216834909_test: SkipByDesign # No FFI on simulators
 dart/sdk_hash_test: SkipSlow # gen_kernel is slow to run on simarm
 dart/sendport_api_test: SkipByDesign # No FFI on simulators
+dart/shared_collect_all_garbage_test: SkipByDesign # No FFI on simulators
+dart/shared_syncstar_test: SkipByDesign # No FFI on simulators
 dart/symbolized_dart_crash_test: Skip # Stack dump code doesn't see simulated stack
 dart/unboxed_param_args_descriptor_test: SkipByDesign # https://dartbug.com/37299 FFI helper not supported on simulator
 dart/unboxed_param_tear_off_test: SkipByDesign # https://dartbug.com/37299 FFI helper not supported on simulator