The title from `toc_tokens` ignores the `smarty` extension

[oprypin]

The title from `toc_tokens` ignores the `smarty` extension

[oprypin]

By the way, please don't solve this by lowering the priority of the toc extension, so much stuff I made already depends on its precise priority 🥲

[waylan]

I didn't have much involvement in the smarty extension, which was added much later than TOC. I wonder why it was given a lower priority. @mitya57 do you recall? I seem to recall you being involved in the development of the smarty extension.

I ask why because, barring any good reason not to, I have no object in raising the priority to be before TOC.

[mitya57]

When I added smarty treeprocessor in 47ec0cb, I probably just pushed it to the end without thinking too much.

The tests pass when changing its priority, so I think it's fine to do that. Submitted PR as #1440.