_format has to be a route requirement not option: enforce it for all Canvas API routes once and for all
>>> [!note] Migrated issue
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<!-- Migrated from issue #3568870. -->
Reported by: [mglaman](https://www.drupal.org/user/2416470)
Related to !490
>>>
<h3 id="overview">Overview</h3>
<p><span class="drupalorg-gitlab-issue-link drupalorg-gitlab-link-wrapper"><a href="https://git.drupalcode.org/project/canvas/-/work_items/3558747" class="drupalorg-gitlab-link">https://git.drupalcode.org/project/canvas/-/work_items/3558747</a></span> added the _format to JSON in one route. Others have it... but in options. It has to be a requirement for \Drupal\Core\Routing\RequestFormatRouteFilter::getAvailableFormats to work.</p>
<h3 id="proposed-resolution">Proposed resolution</h3>
<p>Fix wrong _format in routing.</p>
<h3 id="ui-changes">User interface changes</h3>
issue