Remove commented-out deleteFetcher function from fetchers.ts to clean up code

frontend/src/units/swr/fetchers.ts

@@ -34,11 +34,4 @@ async function mutationFetcher<Command>(url: string, { arg }: { arg: Command })
   }).then(res => res.json());
 }
 
-// async function deleteFetcher<Command>(url: string, { arg }: { arg: Command }) {
-//   return fetch(combine(url, arg as number), {
-//     method: "DELETE",
-//     headers: getHeaders()
-//   }).then(res => res.json());
-// }
-
 export { fetcher, mutationFetcher };