refactor: small cleanups (#2059)

* refactor: remove unneeded async

* chore: add express Router type to all routes

* refactor: don't use index in react key

* refactor: correctly get error message in excel route

* refactor: avoid exporting muteable values

apps/server/src/api-data/session/session.service.ts

@@ -37,7 +37,7 @@ export async function getSessionStats(): Promise<SessionStats> {
 /**
  * Adds business logic to gathering data for the info endpoint
  */
-export async function getInfo(): Promise<GetInfo> {
+export function getInfo(): GetInfo {
   const { version } = getDataProvider().getSettings();
   const { port } = portManager.getPort();