Opt out RNTesterIntegrationTests from Buck2 runs

Summary:
Opts `fbsource//xplat/js/react-native-github/packages/rn-tester:RNTesterIntegrationTests` out of Buck2 runs as the target fails in the analysis stage due to some flavor issues.

I did experiment with just resolving the flavor issues but several more nontrivial issues show up in the build graph the deeper you go and I think this target is going to require a bit more of a deep dive, so just disabling it to unblock buck2 CI rollout for now.

Reviewed By: bujar

Differential Revision: D43505883

fbshipit-source-id: 672dc6aea345a8c0396f6a0e3d549016fe1f7c45

packages/rn-tester/BUCK

@@ -173,6 +173,9 @@ fb_apple_test(
         "UIKit",
     ],
     info_plist = "//xplat/configurations/buck/common_info_plists:ApplicationTest-Info.plist",
+    # There are some flavor dependencies in the call chain that prevent this target from building correctly
+    # using Buck2
+    labels = ["opt-out-buck2-runs"],
     preprocessor_flags = get_objc_arc_preprocessor_flags() + get_preprocessor_flags_for_build_mode(),
     test_host_app = "//fbobjc/Configurations/Buck/CommonTestHost:CommonTestHost",
     visibility = [