CI: pin to jupyter-core<5.8.0 on Windows (#7655)

* Pin `jupyter-core<5.8.0`

* lint

Author: jtpio

.github/workflows/build.yml

@@ -157,6 +157,11 @@ jobs:
         run: |
           ${{ matrix.py_cmd }} -m pip freeze
           ${{ matrix.py_cmd }} -m pip check
+      - name: Temporary pin for jupyter-core on Windows
+        if: matrix.os == 'windows-latest'
+        run: |
+          # See https://github.com/jupyter-server/jupyter_server/issues/1527
+          ${{ matrix.py_cmd }} -m pip install "jupyter-core<5.8.0"
       - name: Validate the install
         run: |
           jupyter labextension list