Upgrade to improve 6950xt bottleneck

Hi all

I am currently running a system with the following specs:

AMD Ryzen 5 5660

B550 Auros Elite V2

Radeon RX 6950XT

(various fans etc)

Corsair 400D case

850W Corsair RM850e

I am looking to update CPU to AM5. Does anyone have any recommendations? I'm looking to spend around £500-600 all in.