swh.auth.pytest_plugin: Make decoded_token consistent with user_info
Tester will want to craft carefully the keycloak mock so it returns consistent data.
Currently the decoded_token and user_info are hard-coded to consistent values. So using the default keycloak mock is ok. As soon as other testers will want another user_info, the decoded token will diverge and not return the correct user_info subpart of the decoded token.
This commits fixes such behavior and allows the decoded token to stay consistent with the user_info.
Related to swh-deposit#2858 (closed)
Migrated from D5230 (view on Phabricator)