[boost] Is it time to raise our required CMake version?

At the moment, our required CMake version is conservatively set to 3.8, and all libraries are recommended to support it. This may be set too low for 2027. The minimum usable Ubuntu on Github Actions is 20.04, which has CMake 3.16. Boost installation requires 3.13. Boost.Python requires 3.14. (These are preexisting requirements, from the very beginning.) Opinions? Does anyone need CMake < 3.13? < 3.16?