Bump actions/download-artifact from 6 to 7

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build-riscv64.yml

@@ -97,7 +97,7 @@ jobs:
 
       - name: Download artifacts
         if: env.RELEASE == 'true'
-        uses: actions/download-artifact@v6
+        uses: actions/download-artifact@v7
         with:
           merge-multiple: true
           pattern: packages-*

.github/workflows/build.yml

@@ -249,7 +249,7 @@ jobs:
         python-version: ${{ matrix.python.major-dot-minor }}
 
     - name: Download artifacts
-      uses: actions/download-artifact@v6
+      uses: actions/download-artifact@v7
       with:
         merge-multiple: true
         pattern: packages-*