What to do with an old pension pot?

During my 20s I moved around a lot and worked different jobs. I was auto-enrolled on pension schemes, which I have recently merged all into one pot with Nest. The total in there is ~9k.

For the last few years I have been working in the Civil Service and the plan (though I'm aware plans can change) is to stay with the CS until retirement. The CS has its own separate pension plan, so I won't be paying any more into the Nest.

So, my question is; what to do with the ~9k in the Nest pension? Just leave it there, forget about it, until retirement? Or is there somewhere more worthwhile I can transfer it, perhaps a SIPP?

I'm in my late-30s now btw, so still a while to go until retirement.

Any thoughts appreciated.