Require C++20 and update to C++20

[jmcarcell]

Since the Key4hep stack and the LCG stack are both on C++20 for some time, we could start using C++20 features. This PR changes the requirements and uses in some places C++20 features.

BEGINRELEASENOTES

• Simplify template code by using concept and require when possible. In some places like the UserDataCollection and GenericParameters it seems that cppyy (3.1.2 with ROOT 6.32.06) doesn't like requires nor concept so they can't be changed for now.
• Use consteval when possible which, unlike constexpr, guarantees evaluation at compile-time
• Remove checks for versions above or below C++20 for the standard
• Use algorithms from std::ranges like std::ranges::find and std::ranges::sort
• Remove the ubuntu workflows since they are built on C++17

ENDRELEASENOTES

[tmadlener]

I am generally very in favor of this. I am not yet entirely sure how to properly reflect this in the podio version. Strictly speaking it could be a breaking change, since we remove a "feature". I think we should at least put some warning / message into a podio tag to check if someone is still building podio with c++17 (and can't easily upgrade to c++20).

We potentially have to change a few of the LCG stacks that we use to have the necessary compiler (and ROOT) support.