fix(benchmarks): increase CLI exec timeout to 300s

The build benchmark runs Rspress under the hood which is significantly
heavier than sync/setup. On CI hardware the 120s timeout was insufficient
for the XL tier, causing ETIMEDOUT failures.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: zrosenbauer

benchmarks/src/helpers/exec.ts

@@ -16,7 +16,7 @@ export function runCli(args: readonly string[], cwd: string): string {
     cwd,
     stdio: 'pipe',
     encoding: 'utf8',
-    timeout: 120_000,
+    timeout: 300_000,
   })
 }