fix(onClickOutside): call handler if click event is fired by a keypress

[sibbng]

Description

Reproduction: https://vueuse.org/core/onclickoutside/

1. Click "Open Modal"
2. Press Tab, your focus is now on "Toggle Dropdown" button
3. Press Space. Dropdown opens but Modal is still there, it should be closed since a click event is fired outside the modal.

Try the same thing by clicking "Toggle Dropdown" first. It works as expected. This PR fixes that inconsistency.

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.