Just noticed the following error in Travis for the data privacy tool:

/home/travis/moodle/admin/tool/dataprivacy/templates/data_deletion.mustache - WARNING: HTML Validation info, line 17: The “button” role is unnecessary for element “input” whose type is “submit”. ( <input type="submit" role="button" class="btn btn-secondary" value="[[go, core]]">)

This refers to the core/single_select template. Might be nice to fix to help plugins get a green build in CIs like Travis.