Update end-to-end tests to use Scaffolding containers

[haydentherapper]

Description

Context: https://github.com/sigstore/scaffolding/tree/main/actions/setup-sigstore-env

The fakeoidc container was reimplemented in this setup as well. We can greatly simplify the end-to-end testing bash script by leveraging the run-containers script.

Previous impl: #4161

[haydentherapper]

Note: This is necessary for testing Rekor v2.