Drop 3.14 from CI test matrix

Only 3.13 is used in Docker (python:3.13-slim), no need to test
against a version we don't run on.

.github/workflows/ci.yml

@@ -31,14 +31,11 @@ jobs:
 
   test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: ["3.13", "3.14"]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.13"
       - name: Install uv
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh