a11y: make calendar day controls non submitting

src/components/tools/TenderCalendar.jsx

@@ -58,6 +58,7 @@ export const TenderCalendar = () => {
         {daysList.map(d => (
           <button
             key={d.key}
+            type="button"
             aria-pressed={selectedDay===d.key}
             aria-label={`${d.date} ${d.label}, ${d.count} ihale`}
             onClick={() => setSelectedDay(d.key)}