Update publish-to-test-pypi.yml

Author: oskarhurst

.github/workflows/publish-to-test-pypi.yml

@@ -98,6 +98,9 @@ jobs:
       - name: Install numpy
         run: pip install numpy
 
+      - name: Install tzdata (Python)
+        run: pip install tzdata
+
       - name: Run tests
         run: pytest tests/