Add workflow for setting up CI environment

.github/actions/setup.yaml

@@ -0,0 +1,26 @@
+name: Setup CI environment
+
+on:
+  workflow_call:
+
+jobs:
+
+  setup:
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - name: Check out repo
+        uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: "pip"
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip uv
+          uv pip install --system -r requirements.txt