Add DuMux 3.8 and update to DUNE 2.9.1

[MakisH]

Closes #73.

Note that the two-scale-heat-conduction tutorial (micro-dumux/macro-dumux) does not build, probably due to the old compiler / STL:

Scanning dependencies of target micro_sim
[ 50%] Building CXX object appl/CMakeFiles/micro_sim.dir/micro_sim.cpp.o
/home/vagrant/tutorials/two-scale-heat-conduction/micro-dumux/appl/micro_sim.cpp:10:10: fatal error: numbers: No such file or directory
   10 | #include <numbers>
      |          ^~~~~~~~~
compilation terminated.

We could debug this further, but we will eventually update the baseline to Ubuntu 24.04. That would, however, need a lot of additional effort, as we already know of a few issues we will face (porting code_aster and maybe ASTE, if the VTK packages are still conflicting). cc @IshaanDesai

[MakisH]

@Fujikawas @mathiskelm this is ready for review, you might have objections.

[MakisH]

@Fujikawas Now I get the Kokkos-related issue when building DuMuX also in the VM 🙈

GitHub Actions VM build log (see the raw logs)

[mathiskelm]

Regarding the issue with the two-scale tutorial not working, this header is not required and could be removed. Can you easily check whether removing this include fixes the problem?

[MakisH]

@Fujikawas Now I get the Kokkos-related issue when building DuMuX also in the VM 🙈

GitHub Actions VM build log (see the raw logs)

I worked around this by setting: -DCMAKE_DISABLE_FIND_PACKAGE_Kokkos=TRUE.

[MakisH]

I don't know why, but I don't seem to be able to start a build of the VM on the GitHub runners anymore. I have already tried clearing the cache and changing to different runners.
I will trigger a clean full build on my local system and merge. Maybe waiting will also help.

The strange thing is that it sometimes works...