Update workflow for tests

Author: astropenguin

.github/workflows/tests.yaml

@@ -26,7 +26,7 @@ jobs:
         with:
           python-version: ${{ matrix.python }}
       - run: pip install setuptools==70.0.0  # temporary
-      - run: pip install poetry==1.8.3 && poetry install
+      - run: pip install poetry && poetry install
       - run: deshima-rawdata download 20231117042946 -e
       - run: python scripts/aste/Configure.py cosmos_20231117042946 out
       - run: python scripts/aste/FitSweep.py