parse_input time dimension error in y0 parsing

[flo-schu]

KeyError: "Dimensions of the input array (1) and the specified dimensions on the data variable 'expression(dimensions=['time'])' did not match. Is a dimension missing from the data variable? You can update it by using sim.config.data_structure.expression.dimensions = [...]"`

• Thrown by: y0 = sim.parse_input("y0", reference_data=sim.observations, drop_dims=["time"])
• Caused by missing dimension of the y0-Dataset -> empty dataset
• Solution: y0 = sim.parse_input("y0", reference_data=sim.observations, drop_dims=[]).isel(time=[0])

Originally posted by @mariegrho in #154