* Update supported Python and PyTorch versions in readme

* Update Python, etc. versions in non-English readmes

These were more out of date than in the English readme. This
updates all the versions the readmes claim the repository is tested
with to the same versions stated in the English readme.

Those versions are current at least in the case of the Python and
PyTorch versions (and less out of date for the others).

* Propagate trailing whitespace fix to model list

This runs "make fix-copies". The only change is the removal of
whitespace. No actual information or wording is changed.

* Update tested TensorFlow to 2.6 in all readmes

Per pinning in setup.py

Unlike Python and PyTorch, the minimum supported TensorFlow version
has not very recently changed, but old versions were listed in all
READMEs.