[bug#47459] brython bump to 3.9.5 and fixes for core-updates branch

[jgart]

Hi Ludo,

Thank you for your suggestions! They are much appreciated. I think I 
incorporated all of them and
bumped brython from 3.9.1 to 3.9.5 since it's been a while... Sorry for the 
delay. I hope this patch finds you
well. The above patch was taken from core-updates.

I tried adding a message via the mumi interface but it never went through...