Bump actions/download-artifact from 4.1.8 to 4.2.1

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4.1.8 to 4.2.1.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4.1.8...v4.2.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -50,7 +50,7 @@ jobs:
         python-version: ['3.8', '3.11']
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/download-artifact@v4.1.8
+    - uses: actions/download-artifact@v4.2.1
       id: download
       with:
         name: python-packages