Python script issues

A number of Python script issues that have been popping up lately, and that should probably be fixed at some point.

@matthieu @mivkov please add to this list, or tag people that could have more issues.

• KeyError: 'text.latex.unicode': affects a lot of scripts.
• TypeError: Got both 'linewidth' and 'lw', which are aliases of one another: found this one in theory/SPH/Kernels/kernels.py
• The p_tqdm import used in examples/HydroTests/BlobTest_3D/make{Slice}Movie.py no longer works with the latest version of p_tqdm (1.3.3) and Python 3.10 because of an issue in p_tqdm itself. The only way to make it work is by downgrading p_tqdm to a 0.x version, which is not a very nice solution. We should probably not rely on modules that don't work.