Bump "tested up to" to WP 6.6

[enricobattocchi]

PRs in the release branches:

Tasks

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1. Sets the WordPress tested up to version to 6.6 #21471
   changelog: other +1
2. Free SVN
3. https://github.com/Yoast/wordpress-seo-premium/pull/4400

PRs in trunk + WP.org SVN:

Tasks

Beta Give feedback

1. Sets the WordPress tested up to version to 6.6 duplicate-post#372
   changelog: other +1
2. Set the WordPress tested up to version to 6.6 yoast-test-helper#230
   changelog: other +1
3. ACF analysis (No PR, direct commit to Git and SVN)
4. Custom field finder (No PR, direct commit to Git and SVN)

PRs in trunk:

Tasks

Beta Give feedback

1. https://github.com/Yoast/wpseo-woocommerce/pull/1010
2. https://github.com/Yoast/wpseo-news/pull/876
3. https://github.com/Yoast/wordpress-seo-local/pull/2536
4. https://github.com/Yoast/wpseo-video/pull/1102

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