Pass the taxonomy of the split tt_id to the 'split_shared_term' filter.

Props mboynes.
See #30335.
Built from https://develop.svn.wordpress.org/trunk@30493


git-svn-id: http://core.svn.wordpress.org/trunk@30482 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Improve cleanup of cached term_ids after shared terms are split.

* If the split term ID is stored as 'default_category', 'default_link_category', or 'default_email_category', update it to the new ID.
* If the split term ID is associated with a nav menu item, update that piece of postmeta to the new ID.

Props mboynes.
See #30335.
Built from https://develop.svn.wordpress.org/trunk@30494


git-svn-id: http://core.svn.wordpress.org/trunk@30483 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Only output an optgroup for installed languages in `wp_dropdown_languages()` if translations are available.

See #30335

Built from https://develop.svn.wordpress.org/trunk@30495


git-svn-id: http://core.svn.wordpress.org/trunk@30484 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add an entry to the changelog for `wp_make_link_relative()` noting that intentional support was added for relative URLs.

See #30373.

Built from https://develop.svn.wordpress.org/trunk@30496


git-svn-id: http://core.svn.wordpress.org/trunk@30485 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Minor syntactical adjustments to the inline documentation for the `revision_text_diff_options` hook.

Converts backticked-inline-code to inline `@see` tags (for the full benefit of Code Reference automagical behavior).

See [30396]. See #24908.

Built from https://develop.svn.wordpress.org/trunk@30497


git-svn-id: http://core.svn.wordpress.org/trunk@30486 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`split_shared_term` is an action, not a filter.

See #30335

Built from https://develop.svn.wordpress.org/trunk@30498


git-svn-id: http://core.svn.wordpress.org/trunk@30487 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove whitespace accidentally introduced in r30498

See #30335

Built from https://develop.svn.wordpress.org/trunk@30499


git-svn-id: http://core.svn.wordpress.org/trunk@30488 1a063a9b-81f0-0310-95a4-ce76da25c4cd