new_docker_build_release2.sh and the Release 2 README reference
rpmbuild/make_rpm_ubuntu26_release2.py, but only make_rpm_ubuntu26.py
existed (used by the jenkins-ci-rme builder). The Release 2 producer is
the same general 5-DEB builder (runtime, sources, ctest-runtime,
ctest-sources, build-pipeline), so add it under the expected name.
make_rpm_ubuntu26.py is kept for the jenkins-ci-rme flow.
Co-Authored-By: Claude Code <noreply@anthropic.com>