Fix several typos and spelling mistakes for 6.6

[swissspidy]

I used a GitHub action to find some spelling mistakes / typos and then manually fixed all of them.

The intention is to fix them all in one go, but not actually commit the GitHub action itself.

Trac ticket:

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Props swissspidy, jucaduca, sergeybiryukov.

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[swissspidy]

@SergeyBiryukov Would appreciate your review here as you're usually the one making this kind of changes.

My idea is to fix the typos as part of https://core.trac.wordpress.org/ticket/60699. The GHA is just for testing, not for committing.

[SergeyBiryukov]

Would appreciate your review here as you're usually the one making this kind of changes.

Curious why wp-admin/includes/ms.php and wp-includes/formatting.php are excluded. Looks great to me otherwise! 👍

[swissspidy]

There were some false positives reported in those files, so it was easier to just ignore them here during development.

[swissspidy]

Committed in https://core.trac.wordpress.org/changeset/57987 / https://core.trac.wordpress.org/changeset/57988

Can do this again periodically I think