Fix a typo in the DocBlock for `WP_Http_Curl::$bytes_written_total` introduced in [29968].

Props kpdesign.
See #26726.

Built from https://develop.svn.wordpress.org/trunk@30767


git-svn-id: http://core.svn.wordpress.org/trunk@30757 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Improve inline documentation for `wpdb::has_cap()`.

Adds a changelog entry for the addition of the 'utf8mb4' feature, accepted values for `$db_cap`, and a return description.

Props kpdesign.
See #21212.

Built from https://develop.svn.wordpress.org/trunk@30768


git-svn-id: http://core.svn.wordpress.org/trunk@30758 1a063a9b-81f0-0310-95a4-ce76da25c4cd