ci: install local package before tests

Author: tillywoodfield

.github/workflows/ci.yml

@@ -9,6 +9,8 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
+      - name: Install local package
+        run: pip install .
       - name: Install dev requirements
         run: pip install -r requirements_dev.txt
       - name: Check black