Merge pull request #37548 from openedx/dependabot/github_actions/actions/download-artifact-6

chore(deps): bump actions/download-artifact from 5 to 6

.github/workflows/unit-tests.yml

@@ -230,7 +230,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - name: collect pytest warnings files
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           pattern: pytest-warnings-json-*
           merge-multiple: true
@@ -289,7 +289,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Download all artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           pattern: coverage-*
           merge-multiple: true