chore: enable codecov for flutter integration tests

[LucasXu0]

Feature Preview

• flutter integration tests
• flutter cloud integration tests
• flutter unit tests

---

PR Checklist

• My code adheres to AppFlowy's Conventions
• I've listed at least one issue that this PR fixes in the description above.
• I've added a test(s) to validate changes in this PR, or this PR only contains semantic changes.
• All existing tests are passing.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 44.03%. Comparing base (7ecf213) to head (f7d3555).
Report is 228 commits behind head on main.

❗ There is a different number of reports uploaded between BASE (7ecf213) and HEAD (f7d3555). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (7ecf213)	HEAD (f7d3555)
appflowy_web_app	1	0

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #6694       +/-   ##
===========================================
- Coverage   74.41%   44.03%   -30.39%     
===========================================
  Files         245     1150      +905     
  Lines        6566    62549    +55983     
  Branches     1057        0     -1057     
===========================================
+ Hits         4886    27542    +22656     
- Misses       1628    35007    +33379     
+ Partials       52        0       -52     

Flag	Coverage Δ
appflowy_web_app	?
flutter_integration_test_cloud_runner	20.34% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_1.dart	19.22% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_2.dart	23.51% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_3.dart	20.03% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_4.dart	14.52% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_6.dart	19.46% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_7.dart	13.49% <ø> (?)
flutter_integration_test_integration_test/desktop_runner_8.dart	13.60% <ø> (?)
flutter_unit_test	8.12% <ø> (?)

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