Remove Werkzeug limitation after flask-login was fixed

[potiuk]

The Werkzeug limitation removed in #25270 can be removed now, when
Flask-login is fixed and 0.6.2 version is released that supports it.

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[potiuk]

Let's not merge this one (yet) flask login 0.6.2 break one of our tests (Google Oauth login). I can reliably reprosuce it but i need to find out if it is a real bug or test issue (i presume the latter - seems like we are mocking some internal call that have changed)

[potiuk]

Actually, this turned to be real error @josh-fell and @jedcunningham - #25318

I think this one actually can have quite a bad effect on our users, I will follow up with flask-login maintainer to verify the actual scope of the problem.

As I see now, some of our users will likely have google openid auth backend stop working if they switch to Flask-Login 0.6.2 (And there is nothing to prevent them from doing so except constraints).

However in the meantime we should merge #25318 to stop main from failing

[potiuk]

Right. I also had to fix the tests because Werkzeug 2.2 suddenly started to return ' instead of ' 🤷