New conda environment

Some scripts (in particular quickplot run-scripts in pyicon/tools/run_qp_driver*.sh) activate a conda environment (e.g. conda_act_mistral_pyicon_env or act_pyicon_py39) which was created with miniconda. Since this environment was created only with packages from the conda-forge channel, there is probably no real license issue. However, it is probably also a good time to switch to a more up-to-date python environment.