perf(alloc): feature for sort_unstable

[jameslkingsley]

• Adds a feature flag for using sort_unstable instead of sort
• Uses conditional compilation instead of cfg! to avoid adding branches
• sort_unstable reduces allocations but can be slower if the Vec is already partially sorted

[sstadick]

Hi @jameslkingsley - not sure how this slipped by me, I will take a look this week. Thank you for the PR!

[sstadick]

Did you happen to get any initial bench numbers on this?

[jameslkingsley]

Think I did run a bench but I didn't save the results anywhere

[sstadick]

@jameslkingsley - openplayuk#1

This adds a benchmark (sort-unstable is faster 👍) and fixes the CI issue / adds the version bump and changelog updates. If you want to review that and merge it into what you have, I can then merge this in.

Or if you'd prefer I can just pull all the changes in from there. Just lmk

[jameslkingsley]

@sstadick awesome, all looks good, merged 👍🏻
Thanks!

[sstadick]

See version 1.3.0

Thanks for the PR @jameslkingsley !