Checklist for updating basic tutorial lessons for v2.8

[rswamina]

This issue addresses basic lesson changes including setup for ESMValTool and ESMValCore 2.8. It references the following checklist from 278.

lesson Configuration:

• Download options in config_user.yml are changed, More details are given in #1935 and the documentation.
• Add instructions on how to download from esgf, see Update instructions on downloading the data before starting the tutorial #275

lesson Running your first recipe:

• recipe_python.yml is changed, updates needed for dataset, preprocessor and location.
• add instructions about location and timerange.

lesson Installation:

• command using mamba does not need python version