test: ignore coverage for untestable line

I'm not sure what the missing coverage is even about

Author: dbartholomae

src/elements/Table.tsx

@@ -36,6 +36,7 @@ function sortKeysInOrderOf<Obj extends Record<string, unknown>>(
 ): (obj: Obj) => Obj {
   return (obj: Obj) =>
     keys.reduce((bodyAccumulator, header) => {
+      /* istanbul ignore next */
       const { [header]: _omitted, ...bodyWithoutHeader } = bodyAccumulator;
       return {
         ...bodyWithoutHeader,