fix(ci): move to macos13

.github/workflows/test.yml

@@ -30,12 +30,6 @@ jobs:
           * fdad:bad:ba55::/64
           EOF
 
-      - name: Download Vagrant boxes for all scenarios
-        # To save some cache space, all scenarios share the same cache key.
-        # On the other hand, this means that the cache contents should be
-        # the same across all scenarios. This step ensures that.
-        run: ./.github/download-boxes.sh
-
       - name: Set up Python ${{ env.PYTHON_VERSION }}
         uses: actions/setup-python@75f3110429a8c05be0e1bf360334e4cced2b63fa # 2.3.3
         id: pip-cache