Revert "mark catalina ios tasks as flaky (#70255)" (#70328)

dev/devicelab/manifest.yaml

@@ -645,14 +645,12 @@ tasks:
       A smoke test that runs on macOS Catalina, which is a clone of the Gallery startup latency test.
     stage: devicelab_ios
     required_agent_capabilities: ["mac-catalina/ios"]
-    flaky: true
 
   smoke_catalina_hot_mode_dev_cycle_ios__benchmark:
     description: >
       A some test that runs on macOS Catalina, which is a clone of the Dart VM hot patching performance benchmarking.
     stage: devicelab_ios
     required_agent_capabilities: ["mac-catalina/ios"]
-    flaky: true
 
   smoke_catalina_start_up:
     description: >