Bump to clang 16

[isuruf]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

Split from #4890

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[jakirkham]

Thanks Isuru! 🙏

[xhochy]

This is the simpler of the two compiler updates.

[jakirkham]

Yeah and that is why we chose just to do Clang 16 and defer on GCC 13 for a bit

[h-vetinari]

I'm fine with this either way. My impression is that clang 16 will be more disruptive than GCC 13 (partially explained in #4890), but in any case, I'm in favour of keeping our compilers up to date.

One more argument in favour of doing only clang is that GCC 12 still receives bugfixes, while clang 15 is dead (actually clang 16 has topped out at 16.0.6 as well, but at least that means it has "converged" to its final state).

[isuruf]

Thanks @h-vetinari for the PR and building clang-16