GCC 13's std::format seems to be less powerfull compared
to {fmt}
* The width cannot be passed as a variable (like in {2})
* The box character "─" cannot be used as a fill char,
  other chars like "*" are working though.

Formatting ranges is not a part of C++20's std::format,
it is proposed in P2286 and might become part of C++23.
As it is only a single occurence, the explicit version
of printing a FieldVector should be sufficient.

[disc][projection] add missing dune functions include

See merge request !3417

Doxygen/remove shell script

See merge request !3416

[ci] add job for doxygen docu build

Closes #1187

See merge request !3367

Fix CI python tests with dune 2.9

See merge request !3403

[ci] temporary fix for conflicts with opm cmake setup

See merge request !3415

Fix/istl solvers can communicate

Closes #1229

See merge request !3413

Feature/seq stokes solver

See merge request !3404

Two minor fixes

See merge request !3407

Newer compilers don't include cstdint implicit, we have to
do it explicit.

Feature/helmholtz operator

See merge request !3401