Bump actions/download-artifact from 4 to 5

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Remove now obsolete step

Add support for ARM architectures

Add $LDAI_RUNTIME_FILE

Fix crash when LDAI_OUTPUT is set (but OUTPUT is not)