Fix xdist dependency change

.github/workflows/tests.yml

@@ -30,7 +30,7 @@ jobs:
     - name: Install testing dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install pytest pytest-timeout pytest-xdist expecttest
+        pip install pytest pytest-timeout pytest-xdist pytest-forked expecttest
     - name: Install torch on mac
       if: startsWith(matrix.os, 'macOS')
       run: pip install --no-cache-dir torch==${{ matrix.torch }} torchvision==${{ matrix.torchvision }}