Broken link to release notes

One-sentence description

The link to the release notes in the announcement section at the top of the page is broken.

Current behaviour / Reproducing the bug

It links to https://gitlab.science.ru.nl/thalia/concrexit/tags/-/v26/, which redirects to https://gitlab.science.ru.nl/thalia/concrexit/-/tags/-/v26, which gives a 404.

Expected behaviour

It should link to https://gitlab.science.ru.nl/thalia/concrexit/-/tags/v26.