adjust python calls to new cluster

[orichters]

Purpose of this PR

• python will not be available on the new cluster, see man python:

unversioned-python The "unversioned" python command (/usr/bin/python) is missing by default. We recommend using python3 or python2 instead. If using the explicit versioned command is inconvenient, you can use alternatives to configure python to launch either Python 3 or Python 2.

• still, this is just a draft because python3.9 is currently missing on the compute nodes, see sbatch --qos=priority --job-name=pythontest --wrap="python3.9 --version" currently returning /var/spool/slurm/d/job406373/slurm_script: line 4: python3.9: command not found

Type of change

• [x] Bug fix

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code
• [x] I explained my changes within the PR, particularly in hard-to-understand areas
• [x] I checked that the in-code documentation is up-to-date
• [x] I adjusted the reporting in remind2 where it was needed
• [x] I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• [ ] All automated model tests pass (FAIL 0 in the output of make test)
• [ ] The changelog CHANGELOG.md has been updated correctly