x/website: wiki CommonMistakes should mention Go 1.22 about loop variables

[callthingsoff]

https://go.dev/wiki/CommonMistakes is not updated after Go 1.22 release.

I see faq is saying:

This behavior of the language, not defining a new variable for each iteration, was considered a mistake in retrospect, and has been addressed in Go 1.22, which does indeed create a new variable for each iteration, eliminating this issue.

[gabyhelp]

Related Issues

• x/wiki: CommonMistakes mention loopvar change in section using-goroutines-on-loop-iterator-variables #65659

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[callthingsoff]

Dup of #65659