Fix CI: Pre-install blis binary for Python 3.9 to avoid compilation

Author: adlumal

.github/workflows/ci.yml

@@ -38,6 +38,11 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-spacy-
 
+      - name: Pre-install blis binary (Python 3.9 fix)
+        if: matrix.python-version == '3.9'
+        run: |
+          pip install --only-binary=blis blis
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip