Bump actions/download-artifact from 4.1.5 to 4.1.6 (#1452)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4.1.5 to 4.1.6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](8caf195ad4...9c19ed7fe5)

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

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

.github/workflows/pull-request.yml

@@ -388,7 +388,7 @@ jobs:
           workload_identity_provider: ${{ secrets.FIREBASE_TEST_LAB_WORKLOAD_IDENTITY_PROVIDER }}
           access_token_lifetime: '900s'
       - name: Download a single artifact
-        uses: actions/download-artifact@8caf195ad4b1dee92908e23f56eeb0696f1dd42d
+        uses: actions/download-artifact@9c19ed7fe5d278cd354c7dfd5d3b88589c7e2395
         with:
           name: Demo app release binaries
       - name: Robo test