correct the unmount lifecyle for amplify-authenticator

[hkjpotato]

Description of changes

Fix the memory leak issue by using the correct lifecycle method to remove event listener when component is unmounted from DOM.

It seems there is no such lifecycle hook called componentWillUnload. Based on the stencil doc https://stenciljs.com/docs/component-lifecycle#disconnectedcallback, it should be disconnectedCallback.

Issue #, if available

Fixes #6840

Description of how you validated changes

• run it locally to see the lifecycle is called and handleExternalAuthEvent is being removed from Hub, and thus fix the memory leak issue.

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Merging #8227 (5a7b0cd) into main (dedd564) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #8227   +/-   ##
=======================================
  Coverage   77.67%   77.67%           
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  Files         236      236           
  Lines       16503    16503           
  Branches     3535     3535           
=======================================
  Hits        12818    12818           
  Misses       3574     3574           
  Partials      111      111           

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[ericclemmons]

Oh my gosh, I can't believe this was missed! Thanks for the fix @hkjpotato !

[github-actions]

This pull request has been automatically locked since there hasn't been any recent activity after it was closed. Please open a new issue for related bugs.

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