[BUG] Typing of layouts.gridplot expects wrong type if ncols given

[levsa]

Software versions

Python version : 3.10.2 (main, Oct 11 2022, 14:44:11) [Clang 14.0.0 (clang-1400.0.29.102)]
IPython version : (not installed)
Tornado version : 6.0.3
Bokeh version : 3.4.1
BokehJS static path : ./.pyenv/versions/3.10.2/envs/dev@3.10.2/lib/python3.10/site-packages/bokeh/server/static
node.js version : v18.4.0
npm version : 8.12.1
jupyter_bokeh version : (not installed)
Operating system : macOS-14.4.1-arm64-arm-64bit

Browser name and version

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Jupyter notebook / Jupyter Lab version

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Expected behavior

mypy check to pass

Observed behavior

mypy finds an error:

error: Argument 1 to "gridplot" has incompatible type "list[figure]"; expected "list[list[Any | None]]"  [arg-type]

Example code

from bokeh import layouts
from bokeh.plotting import figure

figures = [figure(title="figure_1"), figure(title="figure_2")]
grid = layouts.column(layouts.gridplot(figures, ncols=3), data_table)

Stack traceback or browser console output

Proposed fix:

@overload
def gridplot(
    children: list[UIElement | None],
    *,
    sizing_mode: SizingModeType | None = None,
    toolbar_location: LocationType | None = "above",
    ncols: int,
    width: int | None = None,
    height: int | None = None,
    toolbar_options: dict[ToolbarOptions, Any] | None = None,
    merge_tools: bool = True,
) -> GridPlot:
    ...


@overload
def gridplot(
    children: list[list[UIElement | None]],
    *,
    sizing_mode: SizingModeType | None = None,
    toolbar_location: LocationType | None = "above",
    ncols: None,
    width: int | None = None,
    height: int | None = None,
    toolbar_options: dict[ToolbarOptions, Any] | None = None,
    merge_tools: bool = True,
) -> GridPlot:
    ...


def gridplot(
    children: list[UIElement | None] | list[list[UIElement | None]],
    *,
    sizing_mode: SizingModeType | None = None,
    toolbar_location: LocationType | None = "above",
    ncols: int | None = None,
    width: int | None = None,
    height: int | None = None,
    toolbar_options: dict[ToolbarOptions, Any] | None = None,
    merge_tools: bool = True,
) -> GridPlot:
    if ncols:
    
    # implementation here

Screenshots

No response