Please can you support `divan::bench(consts = xxx)`

[joseph-isaacs]

Hey there.

We are really enjoying using CodSpeed (https://codspeed.io/spiraldb/vortex). The consts feature would be really useful for our fastlanes repo, we make extensive use of cosnt generics.

Please do let me know if this is something you think you would support, or if so what sort of timeline would you suggest, how hard to you think it would be to implement?