Added jinja2 upgrade

[annakristinkaufmann]

Fixes #3226

[annakristinkaufmann]

Hi @samuel-kerrien ! The issue reported by @alex4200 comes from the installed package allensdk, which downgrades the jinja2 package. I have added a manual package upgrade to the notebook now.

I had a suggestion regarding the instructions here: I would remove the section "Install Additional Packages" and even the installation of nexusforge since all of these packages are then installed from within the notebook. Unless there is some other reason why those installations had to be run before starting the notebook.

[samuel-kerrien]

Hi Anna, thanks for looking into this ! With respect to your proposal on updating the Python Setup instruction, I guess we can't remove the Jupyterlab part but I agree, we can take out the libs that are specific to what you run inside the notebook (forge, allensdk and neurom).

Here is a visual of what I would propose we take out (in red rectangles):

Do you want to include that in your PR for completeness ?

[bogdanromanx]

@samuel-kerrien, could you please have a look at this PR?