Fix duplicate-word and spelling typos in docblocks and comments

[khokansardar]

Several docblocks and inline comments in WordPress core contain duplicated words (the the, in in, on on, is is, from from, and and) and one minor misspelling (Compatability). These do not affect runtime behavior but reduce documentation quality.

This ticket proposes correcting WordPress-owned files only, leaving third-party/bundled libraries (ID3, PHPMailer, SimplePie, plupload, jQuery UI) to be handled upstream.

Affected areas:

• src/wp-includes/ (fonts.php, comment.php, block-template.php, block-supports/settings.php, rest-api/class-wp-rest-server.php, class-wp-customize-manager.php, class-wp-theme-json-data.php, class-wp-recovery-mode-email-service.php)
• src/js/_enqueues/ (wp/dashboard.js, wp/widgets/custom-html.js, deprecated/fakejshint.js)
• tests/phpunit/ (9 comment/docblock fixes)

Corrects duplicated words (such as "the the", "in in", "on on", "is is", "from from", "and and") and a misspelling ("Compatability") in WordPress-owned docblocks and inline comments across src/ and the PHPUnit test suite. These are comment-only edits with no functional or behavioral change.

Third-party and bundled libraries (ID3, PHPMailer, SimplePie, plupload, jQuery UI, etc.) are intentionally left untouched, as they are maintained upstream.

Trac ticket: https://core.trac.wordpress.org/ticket/65384

## Use of AI Tools

N/A

[desrosj]

Assigning good first bug to mark claimed.

## Use of AI Tools
N/A

Is this accurate?

## Use of AI Tools
N/A

Is this accurate?

Sorry I missed it.

[sanayasir]

Tested by reviewing the patch diff on WordPress trunk.

Verified that the duplicated words and the misspelling ("Compatability") have been corrected across the affected WordPress-owned files. Confirmed that the changes are limited to comments and docblocks and do not introduce any functional modifications.

The documentation updates are accurate and the patch looks good.

Patch tests well. ✅

[sanayasir]

Please consider the new patch/diff file and ignore the previous one.

[tusharaddweb]

Tested patch locally.

All typo and duplicate-word corrections checked across the listed PHP, JavaScript, and test files.

Changes are accurate, properly scoped (third-party libs excluded), and have no runtime impact. Documentation is cleaner now.

[westonruter]

In 62489:

Docs: Fix duplicate-word and spelling typos in comments and docblocks.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/12039.

Props khokansardar, sabernhardt, sanayasir, tusharaddweb.
Fixes #65384.