AH: modified conda recipe

Edited How_to_work_after_the_course.txt

Added section on how to install conda environemnt on Levante and to access that environment from juypterhub

I also added some more packages to be installed into pyco_202503, like cdo, requests, etc...

I tested the installation of pyco_202503 on Levante and locally. In both cases, all python course notebooks are running. I also added an instruction on how to install the conda environment in a user-defined directory (e.g. /work)

@k204045 Could you please check before merging this into main? My edits are just a proposal....

Thanks and cheers Angelika