Release GPU nightly has no runner

e2e-nightly-release.yml runs its e2e job on [self-hosted, gpu, libreyolo-e2e], and the repo has no registered runner, so the post-publish nightly for v1.6.0 (run 36343418148) stays queued forever. The v1.6.0 tag was verified by running tools/ci/modal_nightly.py --ref 809009bc directly (passed). Either reconnect the runner or run the release job on Modal like the dev nightly.