Bump actions/download-artifact from 4 to 5 (#6901)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/test_fast.yml

@@ -157,7 +157,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Download coverage artifacts
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
 
       - name: Codecov upload
         uses: codecov/codecov-action@v5

.github/workflows/test_functional.yml

@@ -329,7 +329,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Download coverage artifacts
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
 
       - name: Codecov upload
         uses: codecov/codecov-action@v5