ci: run pytest via uv run so the matrix interpreter is honored

Address code review: the previous uv venv + uv pip + uv run sequence could run pytest in a different environment than the matrix Python. Use a single uv run --python ... --with . --with pytest invocation (mirrors noxfile). Also correct the stale Black target-version note in CLAUDE.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/test.yml

@@ -17,14 +17,5 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@v5
 
-      - name: Install Python ${{ matrix.python-version }}
-        run: uv python install ${{ matrix.python-version }}
-
-      - name: Create venv
-        run: uv venv --python ${{ matrix.python-version }}
-
-      - name: Install project and pytest
-        run: uv pip install . pytest
-
       - name: Run smoke tests
-        run: uv run pytest -v
+        run: uv run --python ${{ matrix.python-version }} --with . --with pytest pytest -v