Add CI workflow for release binaries

If #4 is merged, prebuilt EchoFrame ZIPs will be expected to live on GitHub Releases, but they are still produced manually. Add a release-build workflow that builds the supported CUDA/MATLAB matrix and uploads the ZIPs as release assets, or document any runner/toolchain limits that require keeping this manual.

ci: build release binary assets

Pending on testing for PR, will be closed later if everything goes well