[scripts] Remove calls to sys.exit from Python functions

NEWS.txt

examples/python3/TelApy_api/art.py

examples/python3/TelApy_api/mascaret.py

examples/python3/TelApy_api/mascaret_tracer.py

examples/python3/TelApy_api/t2d.py

examples/python3/TelApy_api/t2d_cin.py

examples/python3/TelApy_api/t2d_gai.py

examples/python3/TelApy_api/t2d_restart.py

examples/python3/TelApy_api/t3d.py

examples/python3/TelApy_api/t3d_gai.py

examples/python3/TelApy_api/t3d_waq.py

examples/python3/TelApy_api/test_recompile.py

examples/python3/TelApy_api/vnv_api.py

examples/python3/TelApy_api/vnv_api_mascaret.py

examples/python3/TelApy_api/wac.py

examples/python3/TelApy_hermes/read_write.py

examples/python3/TelApy_hermes/read_write_format.py

examples/python3/TelApy_hermes/test_telemac_file.py

examples/python3/TelApy_hermes/vnv_hermes.py

examples/python3/telapy_coupling/vnv_coupling.py