fix: void-wrap updateTokenStats call to match BackendFacadeDeps signature

BackendFacadeDeps.updateTokenStats is typed as () => Promise<void>, but
updateTokenStats() returns Promise<DetailedStats | undefined>. The void
operator discards the return value so the arrow function satisfies the
expected type without changing behaviour.

Author: rajbos

vscode-extension/src/extension.ts

@@ -7844,7 +7844,7 @@ export async function activate(context: vscode.ExtensionContext) {
       context,
       log: (m: string) => tokenTracker.log(m),
       warn: (m: string) => tokenTracker.warn(m),
-      updateTokenStats: () => tokenTracker.updateTokenStats(),
+      updateTokenStats: () => void tokenTracker.updateTokenStats(),
       calculateEstimatedCost: (modelUsage: ModelUsage) => tokenTracker.calculateEstimatedCost(modelUsage),