[FIX] type: Fix the Alias type

The Alias introduced to prevent Intellisense to resolve simple aliases
was broken. As a reminder, it allows us for example to type specific
string as `UID` and prevent the variables to be noted as `string`later
on in the code.

Part-of: odoo/o-spreadsheet#2300

src/types/misc.ts

@@ -13,7 +13,7 @@ import { Range } from "./range";
  * Intellisense from resolving it.
  * See https://github.com/microsoft/TypeScript/issues/31940#issuecomment-841712377
  */
-export type Alias = {};
+export type Alias = {} & {};
 
 // Col/row Index
 export type HeaderIndex = number & Alias;