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](https://github.com/actions/download-artifact/compare/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>

.github/workflows/manage-prs.yml

@@ -147,7 +147,7 @@ jobs:
           location: ${{ runner.temp }}
 
       - name: Download diff
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           path: ${{ needs.diff.outputs.path }}
           name: ${{ needs.diff.outputs.artifact }}
@@ -475,7 +475,7 @@ jobs:
 
     steps:
       - name: Download submission check failure flag artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           path: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PATH }}
           pattern: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PREFIX }}*

.github/workflows/sync-labels.yml

@@ -108,7 +108,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Download configuration file artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           merge-multiple: true
           pattern: ${{ env.CONFIGURATIONS_ARTIFACT_PREFIX }}*