ci(deps): bump actions/download-artifact from 5 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/release.yml

@@ -73,7 +73,7 @@ jobs:
             throw new Error('Package-build workflow did not complete successfully within 10 minutes');
 
       - name: Download build artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: packages
           path: artifacts/

.github/workflows/test-build.yml

@@ -75,7 +75,7 @@ jobs:
     - uses: actions/checkout@v5
 
     - name: Download built deb
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v6
       with:
         name: deb-${{matrix.host_release}}