Add missing requirements.txt and venvs for Python tutorials

[NiklasVin]

Adds the missing requirements.txt files mentioned in #547 and modifies the run scripts accordingly.

I followed the approach suggested here: #547 (comment) to prevent redundant requirement files.
This concerns the following tutorials:

• partitioned-heat-conduction
• partitioned-heat-conduction-complex
• partitioned-heat-conduction-overlap
• volume-coupled-diffusion
• oscillator-overlap
• oscillator

[MakisH]

I have not tried to run or check if each requirements.txt included all and the correct dependencies, but the changes look good.

Thanks also for catching and fixing some small inconsistencies (e.g., forgotten close_log, or initializing the venv before starting to log)!

[BenjaminRodenberg]

Thank you for the PR! This really gives a very good overview of the current state and where we have to clarify some questions. I added some comments to point to the open issues. I will briefly summarize here:

• Generally restrict numpy.
• Is mpi4py actually a fenicsprecice dependency? Move it there?
• If pyprecice is a fenicsprecice dependency move it there
• Find a good approach for FEniCS

I would suggest to merge #564 and #557 independently from this PR because I expect that we are quicker with these smaller PRs.

[NiklasVin]

If pyprecice is a fenicsprecice dependency move it there

I saw that pyprecice is a dependency of fenicsprecice, so I am going to remove it from the requirements👍

[BenjaminRodenberg]

Looks good 👍

Just a few minor (non-critical) point left. We can merge this PR as it is or you can quickly take care about the fixes.

I will merge this PR latest over the weekend.