When OIDCProxy has verify_id_token=True and the IdP issues the same JWT
for both access_token and id_token, the value-equality check
`verification_token != upstream_token_set.access_token` evaluated to
False, skipping the scope patch entirely. This left AccessToken.scopes
empty, causing RequireAuthMiddleware to return 403 insufficient_scope.
Replace the value-equality check with an intent-based virtual method
`_uses_alternate_verification()` that OIDCProxy overrides to return
`self._verify_id_token`. The base OAuthProxy returns False (preserving
existing behavior for non-OIDC providers).
Fixes#3461
Co-authored-by: voidborne-d <voidborne-d@users.noreply.github.com>
