disable iomgr cfstream test

tools/run_tests/run_tests.py

@@ -1164,15 +1164,16 @@ class ObjCLanguage(object):
 
         # TODO(jtattermusch): move the test out of the test/core/iomgr/CFStreamTests directory?
         # How does one add the cfstream dependency in bazel?
-        out.append(
-            self.config.job_spec(
-                ["test/core/iomgr/ios/CFStreamTests/build_and_run_tests.sh"],
-                timeout_seconds=60 * 60,
-                shortname="ios-test-cfstream-tests",
-                cpu_cost=1e6,
-                environ=_FORCE_ENVIRON_FOR_WRAPPERS,
-            )
-        )
+        # Disabled due to flakiness and being replaced with event engine
+        # out.append(
+        #     self.config.job_spec(
+        #         ["test/core/iomgr/ios/CFStreamTests/build_and_run_tests.sh"],
+        #         timeout_seconds=60 * 60,
+        #         shortname="ios-test-cfstream-tests",
+        #         cpu_cost=1e6,
+        #         environ=_FORCE_ENVIRON_FOR_WRAPPERS,
+        #     )
+        # )
         return sorted(out)
 
     def pre_build_steps(self):