inline syncedKeys and remove SyncedMemento type

src/vs/vscode.proposed.d.ts

@@ -2181,20 +2181,16 @@ declare module 'vscode' {
 	//#endregion
 
 	//#region Syncing Extension's Global State https://github.com/microsoft/vscode/issues/95209 @sandy081
-
 	export interface ExtensionContext {
-		readonly syncedGlobalState: SyncedMemento;
-	}
-
-	export interface SyncedMemento extends Memento {
 
-		/**
-		 * List of keys whose values should be synced across devices when extensions synchronization is enabled .
-		 * Set synced keys to an empty array to unset the synced state.
-		 */
-		syncedKeys: ReadonlyArray<string>;
+		readonly syncedGlobalState: Memento & {
+			/**
+			 * List of keys whose values should be synced across devices when extensions synchronization is enabled .
+			 * Set synced keys to an empty array to unset the synced state.
+			 */
+			syncedKeys: ReadonlyArray<string>;
+		};
 
 	}
-
 	//#endregion
 }