=== Description
Currently, the table of contents assumes that the sticky header is always shown and offsets its `top` property to account for the sticky header's height. For example, login and visit https://en.wikipedia.beta.wmflabs.org/wiki/Dog?tableofcontents=1&vectorstickyheader=0 and then scroll down the page:
{F34951836}
However, the sticky header may not be enabled or may not be enabled for specific pages. Therefore, we need to make this offset conditional and based on whether the sticky header is/will be shown.
=== Acceptance Criteria
[] Table of contents offsets its top position to account for the sticky header's height only when the sticky header is/will be shown
== Developer Notes
The sticky header has a utility class `.mw-sticky-header-element` that we could make use of here:
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Vector/+/762559