widget test on macos is unstable

[sensuikan1973]

https://github.com/sensuikan1973/pedax/actions/runs/4975981427/jobs/8903652334

❌ /Users/runner/work/pedax/pedax/test/home_test.dart: play a game a game without pass (failed)
  ══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
  The following TestFailure was thrown while running async test code:
  Expected: <5>
    Actual: <2>
  
  When the exception was thrown, this was the stack:
  #0      fail (package:matcher/src/expect/expect.dart:149:31)
  #1      _expect (package:matcher/src/expect/expect.dart:144:3)
  #2      expect (package:matcher/src/expect/expect.dart:56:3)
  #3      expect (package:flutter_test/src/widget_tester.dart:459:16)
  #4      expectStoneNum (file:///Users/runner/work/pedax/pedax/test_helper/board_finder.dart:18:3)
  #5      main.<anonymous closure>.<anonymous closure>.<anonymous closure> (file:///Users/runner/work/pedax/pedax/test/home_test.dart:147:9)
  <asynchronous suspension>
  
  The exception was caught asynchronously.
  ════════════════════════════════════════════════════════════════════════════════════════════════════
  Test failed. See exception logs above.
  The test description was: a game without pass