ci: Move devbuilds to test workflow. Upload artifacts from test builds. Merge Dockerfiles and clone based on ARG BRANCH_OR_TAG. Change prefix of dependabot branch names

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 2.4.1 to 2.5.0.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v2.4.1...v2.5.0

)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 2.4.0 to 2.4.1.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v2.4.0...v2.4.1

)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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