[Dune] Increase minimal GCC version from 9 to 10?

[Christoph Grüninger]

Dear Dune users and developers,

I want to increase Dune Core master's (will become Dune 2.10) minimal 
required GCC version from 9 to 10. Debian 11 comes with GCC 10. Ubuntu 
20.04 provides a package gcc-10, so it is easy to use Dune with Ubuntu 
22.04.
Is there any reason to not increase the minimal compiler to GCC 10?

In the Dune developer meeting 2022, we decided to increase the GCC 
version to 10, unless we are presented cases not considered. [1]
You can answer to this mailing list, write me a private mail, or discuss 
the issue for this topic #353, see [2].

[1] 
https://dune-project.org/community/meetings/2022-02-devmeeting/#minimum-versions-of-gcc-clang-cmake-python
[2] https://gitlab.dune-project.org/core/dune-common/-/issues/353

Bye
Christoph