Introduction to React Testing: Remove unnecessary mention of FireEvent

[nikitarevenco]

Because

I don't really think there's a need to mention FireEvent when it's mentioned that it's deprecated. I don't think there's a need to say that it's an "alternative", or go into any detail into it.

This PR

• Removes mention of FireEvent

Issue

Closes #XXXXX

Additional Information

Pull Request Requirements

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• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
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• The This PR section has a bullet point list describing the changes in this PR
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[MaoShizhong]

Thanks, @nikitarevenco - agreed on this. Could you resolve the merge conflict present? Doing so should auto-resolve the remaining lint errors, as they were resolved in a separate merged PR.

[nikitarevenco]

Thanks, @nikitarevenco - agreed on this. Could you resolve the merge conflict present? Doing so should auto-resolve the remaining lint errors, as they were resolved in a separate merged PR.

Okay, should be good now