Improve task expansion

[fisker]

fast-glob accepts array as patterns, so we don't need flat tasks.

I'm not sure if this improves performance, but I don't think it will be slower.

In generateGlobTasks we can also avoid use multiple task, but I don't if worth to improve that part.

The benchmark test is broken, maybe I can tell if we fix that?

[sindresorhus]

And if it's slower, it should ideally be fixed in fast-glob, so it benefits everyone.

[sindresorhus]

The benchmark test is broken, maybe I can tell if we fix that?

Feel free to fix it, but simple benchmarks don't usually tell the full story. It only focuses on one specific performance case.