ci: install just binary before test step

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: Mjboothaus

.github/workflows/ci.yml

@@ -26,6 +26,11 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+      - name: Install just
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y just
+          just --version
 
       - name: Install dependencies
         run: uv sync --extra dev