Update oic and Flask-pyoidc dependencies

[ccooper]

Renovate tried to take care of this in #339, but the pinned Flask-pyoidc version requires oic 0.9.1.0.

I'd suggest moving back to the origin from the pinned Flask-pyoidc version at the same time. The pinned version only seems to have formatting and docstring changes. However, the root Flask-pyoidc module is multiple versions ahead, so this will involve more work to update.

AFAICT, the biggest change will be in how we call OIDCAuthentication. The class now accepts (potentially) multiple providers, so we'll need to pass that in. Example is here.

[ccooper]

Sigh, this still erroring out while authenticating in prod. It is not straightforward, and the test coverage is abysmal. I'm going to stop messing with something as important as auth and leave this to someone else after I revert.