update and fix large parts of the test suite

conftest.py

src/pystencilssfg/cli.py

src/pystencilssfg/config.py

src/pystencilssfg/context.py

src/pystencilssfg/emission/file_printer.py

src/pystencilssfg/generator.py

tests/extensions/test_sycl.py

tests/generator/test_config.py

tests/generator_scripts/source/BasicDefinitions.py

tests/generator_scripts/source/Conditionals.py

tests/generator_scripts/source/JacobiMdspan.py

tests/generator_scripts/source/MdSpanFixedShapeLayouts.py

tests/generator_scripts/source/MdSpanLbStreaming.py

tests/generator_scripts/source/ScaleKernel.py

tests/generator_scripts/source/StlContainers1D.py

tests/generator_scripts/source/SyclBuffers.py

tests/ir/test_postprocessing.py