Some OIDC providers like Keycloak (v18+) include an `iss` (issuer) parameter in the authentication response for security (as per RFC 9207). The oidc route was explicitly extracting only `code` and `state`, thus losing the `iss` parameter and other potential parameters like `session_state`. When Jackson passed the incomplete set of parameters to `openid-client`, the library failed validation with the error `invalid response encountered` because it expected the `iss` parameter to be present if the server supports it.
Fixes#22238.
Co-authored-by: Sahitya Chandra <sahityajb@gmail.com>
