Enable strict lints

An attempt to fix https://github.com/vector-im/element-call/issues/1132

src/button/LinkButton.tsx

@@ -46,7 +46,7 @@ export function LinkButton({
     <Link
       className={classNames(
         variantToClassName[variant || "secondary"],
-        sizeToClassName[size],
+        size ? sizeToClassName.lg : [],
         className
       )}
       to={to}