Disable flaky test TestQuantLoweringCustomBackendPass (#2465)

Summary:
Pull Request resolved: #2465

imported-using-ghimport

Test Plan: Imported from OSS

Reviewed By: huydhn

Differential Revision: D54966578

Pulled By: guangy10

fbshipit-source-id: a72067fc6cfccc9e53ef0c158919681ba03fd4d8

Author: guangy10

exir/tests/TARGETS

@@ -247,6 +247,7 @@ python_unittest(
         "test_quant_lowering_custom_backend_pass.py",
     ],
     deps = [
+        "//caffe2:test-lib",  # @manual
         "//caffe2:torch",
         "//executorch/exir:lib",
         "//executorch/exir:pass_base",

exir/tests/test_quant_lowering_custom_backend_pass.py

@@ -65,6 +65,7 @@
 from torch.fx import subgraph_rewriter
 from torch.fx.passes.infra.pass_base import PassResult
 from torch.testing import FileCheck
+from torch.testing._internal.common_utils import IS_LINUX
 
 
 # pyre-ignore
@@ -506,6 +507,9 @@ class TestQuantLoweringCustomBackendPass(unittest.TestCase):
     def setUp(self) -> None:
         super().setUp()
 
+    @unittest.skipIf(
+        IS_LINUX, "Flaky test on Linux x86, needs debugging. Issue is tracked in #2468"
+    )
     @torch.inference_mode()  # TODO Use  for capturing.
     def test(self) -> None:
         mod = TestModel(