Fix flaky doctest with NUMBER doctest option from pytest (#7893)

Co-authored-by: Marton Gunyho <[email protected]>

Author: mgunyho

xarray/core/dataarray.py

@@ -6258,9 +6258,11 @@ def curvefit(
         Fit the exponential decay function to the data along the ``time`` dimension:
 
         >>> fit_result = da.curvefit("time", exp_decay)
-        >>> fit_result["curvefit_coefficients"].sel(param="time_constant")
+        >>> fit_result["curvefit_coefficients"].sel(
+        ...     param="time_constant"
+        ... )  # doctest: +NUMBER
         <xarray.DataArray 'curvefit_coefficients' (x: 3)>
-        array([1.05692036, 1.73549639, 2.94215771])
+        array([1.0569203, 1.7354963, 2.9421577])
         Coordinates:
           * x        (x) int64 0 1 2
             param    <U13 'time_constant'