toward fenicsx upgrade second commit

conda/env.yaml

src/bvpy/boundary_conditions/dirichlet.py

src/bvpy/domains/primitives.py

src/bvpy/utils/io.py

src/bvpy/utils/post_processing.py

src/bvpy/utils/visu.py

tutorials/bvpy_tutorial_1_hello_world.ipynb

tutorials/bvpy_tutorial_7_hyper_elasticity.ipynb