attempt to fix integration tests

Author: zhongkechen

.github/workflows/integration-tests.yml

@@ -50,6 +50,7 @@ jobs:
       run: |
         echo "Running Testing SDK tests against Language SDK PR changes..."
         echo "Using Language SDK from: $AWS_DURABLE_SDK_URL"
+        hatch run -- pip install -e ../language-sdk
         python -m pip install -e .
         hatch fmt --check
         hatch run types:check