The #toc macro requires programming rights for numbering sections

The bad lines are:

#set ($context.context.tocNumbered = $numbered)
#set ($context.context.tocData = $tocData)

The first one is not needed at all, since the context is already updated in com.xpn.xwiki.api.Document.getTOC(). The second line is needed because the XWikiHeading filter that generates headings uses the already generated headings instead of recounting the headers. This can be fixed by using vcontext instead of xcontext as the place to store tocData.