Import cell line fighting between Marimo and Ruff

[Antyos]

Describe the bug

There seems to be fighting between how Ruff and Marimo want to save cells containing import statements.

Marimo wants to format them (when saving a notebook, not even formatting a cell) as:

@app.cell
def _():
    import datetime
    return

However, Ruff prefers to format them as:

@app.cell
def _():
    import datetime

    return

Will you submit a PR?

• Yes

Environment

Details

```python
{
  "marimo": "0.18.4",
  "editable": false,
  "location": "C:/Users/Andrew/Code/Project/code/.venv/Lib/site-packages/marimo",
  "OS": "Windows",
  "OS Version": "11",
  "Processor": "Intel64 Family 6 Model 198 Stepping 2, GenuineIntel",
  "Python Version": "3.13.9",
  "Locale": "en_US",
  "Binaries": {
    "Browser": "143.0.7499.110",
    "Node": "v22.21.1"
  },
  "Dependencies": {
    "click": "8.2.1",
    "docutils": "0.22",
    "itsdangerous": "2.2.0",
    "jedi": "0.19.2",
    "markdown": "3.8.2",
    "narwhals": "2.2.0",
    "packaging": "25.0",
    "psutil": "7.0.0",
    "pygments": "2.19.2",
    "pymdown-extensions": "10.16.1",
    "pyyaml": "6.0.2",
    "starlette": "0.47.3",
    "tomlkit": "0.13.3",
    "typing-extensions": "4.15.0",
    "uvicorn": "0.35.0",
    "websockets": "15.0.1"
  },
  "Optional Dependencies": {
    "altair": "6.0.0",
    "duckdb": "1.3.2",
    "loro": "1.5.4",
    "mcp": "1.18.0",
    "nbformat": "5.10.4",
    "openai": "1.102.0",
    "pandas": "2.3.2",
    "polars": "1.32.3",
    "pyarrow": "21.0.0",
    "pytest": "8.4.1",
    "python-lsp-ruff": "2.2.2",
    "python-lsp-server": "1.13.1",
    "ruff": "0.12.11",
    "sqlglot": "27.9.0",
    "vegafusion": "2.0.3",
    "watchdog": "6.0.0"
  },
  "Experimental Flags": {}
}

</details>


### Code to reproduce

_No response_

[dmadisetti]

Thanks, we can defer to ruff.