Fix docstrings for combine_by_coords

[gtrevisan]

Docstrings for combine_attrs parameter show a wrong default value, which is no_conflicts, not drop.

xarray/xarray/core/combine.py

Lines 653 to 661 in 014ab81

	def combine_by_coords(
	data_objects: Iterable[Dataset | DataArray] = [],
	compat: CompatOptions = "no_conflicts",
	data_vars: Literal["all", "minimal", "different"] | list[str] = "all",
	coords: str = "different",
	fill_value: object = dtypes.NA,
	join: JoinOptions = "outer",
	combine_attrs: CombineAttrsOptions = "no_conflicts",
	) -> Dataset | DataArray:

[headtr1ck]

Thanks for this nice little PR :)

Just a tip for next time: make these changes on a branch in your forked repo. Otherwise you will run into problems for your next contribution!