🧹 Remove unused UriScheme import in src/virtualFileSystem.ts

Removed the unused `UriScheme` import from `src/virtualFileSystem.ts` to improve code hygiene and maintainability.

Co-authored-by: zknpr <96851588+zknpr@users.noreply.github.com>

Author: google-labs-jules[bot]

src/virtualFileSystem.ts

@@ -1,6 +1,5 @@
 import * as vsc from 'vscode';
 import { DocumentRegistry } from './documentRegistry';
-import { UriScheme } from './config';
 import { Disposable } from './lifecycle';
 
 import type { DatabaseDocument } from './databaseModel';