CI: use array_api_strict main branch for testing

Author: ev-br

.github/workflows/test.yml

@@ -26,8 +26,9 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install array-api-strict
+        python -m pip install https://github.com/data-apis/array-api-strict.git
         python -m pip install -r requirements.txt
+        python -c'import array_api_strict; print(array_api_strict.__file__)'
     - name: Run the test suite
       env:
         ARRAY_API_TESTS_MODULE: array_api_strict