Bump actions/download-artifact from 7 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v7...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/test-wheels.yml

@@ -45,7 +45,7 @@ jobs:
       uses: actions/checkout@v6
 
     - name: Downloading wheels artifact
-      uses: actions/download-artifact@v7
+      uses: actions/download-artifact@v8
       with:
         path: python-wheels
         merge-multiple: true

.github/workflows/windows-wheels.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
     - name: Downloading Wheels artifact
-      uses: actions/download-artifact@v7
+      uses: actions/download-artifact@v8
       with:
         path: python-wheels
         merge-multiple: true