Merge branch 'update-pipfiles' into 'develop'

.gitlab-ci.yml

ci/matrix/mpl_35_py39/Pipfile

ci/matrix/mpl_35_py39/Pipfile.lock

ci/matrix/mpl_36_py310/Pipfile

ci/matrix/mpl_36_py310/Pipfile.lock

ci/matrix/mpl_37_py311/Pipfile.lock

ci/matrix/mpl_38_py310/Pipfile.lock

ci/matrix/mpl_38_py311/Pipfile.lock

ci/matrix/mpl_38_py312/Pipfile.lock

ci/matrix/mpl_38_py39/Pipfile.lock

ci/matrix/mpl_39_py312/Pipfile

ci/matrix/mpl_39_py312/Pipfile.lock

ci/matrix/mpl_39_py312/Pipfile.lock.license

tests/test_combined.py

tests/test_combined_icon.py

tests/test_plot2d.py

tests/test_plot2d_icon.py

tests/test_plot2d_icon_edge.py

tests/test_vector.py

tests/test_vector_icon.py