chore(ci): easy manual builds for binaries (#2890)

## Description

Can now be used to generate artifacts without having to batch it
together with making a release.

## Breaking Changes

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

.github/workflows/release.yml

@@ -280,6 +280,13 @@ jobs:
             upload_url: ${{ github.event.inputs.upload_url || needs.create-release.outputs.upload_url }}
             asset_path: ${{ env.ASSET }}
 
+        - name: attach artifacts
+          uses: actions/upload-artifact@v4
+          with:
+            name: iroh-${{env.RELEASE_OS }}-${{env.RELEASE_ARCH}}-bundle
+            path: ${{ env.ASSET }}
+            compression-level: 0
+
     docker:
       needs: build_release
       uses: './.github/workflows/docker.yaml'