Incorrect `@return` documentation for `wp_set_object_terms()` and friends

[boonebgorges]

wp_set_object_terms() and its wrappers state in their doc blocks that the return value is an array of term IDs. This is incorrect. The return value is, for better or for worse, term taxonomy IDs. The distinction matters less as shared terms start to go away, but the numbers will be perpetually different for legacy terms (or cases where shared terms have not been split) so the documentation should be fixed.

[boonebgorges]

In 36896:

Correct @return annotation for wp_set_object_terms() and related functions.

The return value is an array of term taxonomy IDs, not term IDs.

Fixes #36182.