fix: dealloc InAppWebViewManager

[letrungdo]

Resolve issue #2512

[violet-dev]

Do you have any plans to merge this pr?
I'm having the same issue so it would be good if it could be merged
cc @pichillilorenzo

[lristic1310]

hey @letrungdo, are there any plans to merge this? Having trouble on the project with this

[letrungdo]

hey @letrungdo, are there any plans to merge this? Having trouble on the project with this

@lristic1310 I don't have permission to merge this PR.
You can go to pubspec.yaml and edit like this to use

flutter_inappwebview:
    git:
      url: https://github.com/guide-inc-org/guide-flutter_inappwebview.git
      path: flutter_inappwebview
      ref: sbi_fx_pc/v6.2.0-beta.3

[jidanyu]

i used 'sbi_fx_pc/v6.2.0-beta.3', but still has the problem, process Pending when using windowManager.close() or exit(0)