build(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/build_wheels.yml

@@ -65,11 +65,11 @@ jobs:
             os: ubuntu-latest
             cibw_archs_linux: auto32
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: sdist
           path: dist
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: tests
           path: tests
@@ -104,11 +104,11 @@ jobs:
           - os: macos-14
             arch: arm64
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: sdist
           path: dist
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: tests
           path: tests
@@ -163,7 +163,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'release' && github.event.action == 'published'
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           # with no name set, it downloads all of the artifacts
           path: dist