Fix _assign_time_coord crash when lead_time is not 1D along forecast_step (#1897)

* Fix _assign_time_coord crash when lead_time is not 1D along forecast_step

* Minor changing to better check what is wrong with the lead_time coordinate

---------

Co-authored-by: Savvas Melidonis <s.melidonis@fz-juelich.de>
Co-authored-by: Savvas Melidonis <79579567+SavvasMel@users.noreply.github.com>

Author: jehangirawan

packages/evaluate/src/weathergen/evaluate/plotting/plot_utils.py

@@ -178,9 +178,21 @@ def _assign_time_coord(selected_data: list[xr.DataArray]) -> tuple[xr.DataArray,
     time_dim = "lead_time"
 
     for i, data in enumerate(selected_data):
-        if data.coords["lead_time"].shape == data.coords["forecast_step"].shape:
+        lead_time = data.coords["lead_time"]
+        forecast_step = data.coords["forecast_step"]
+
+        if (
+            lead_time.dims == forecast_step.dims
+            and lead_time.shape == forecast_step.shape
+            and lead_time.ndim == 1
+        ):
             selected_data[i] = data.swap_dims({"forecast_step": "lead_time"})
-
+        else:
+            _logger.warning(
+                "lead_time coordinate is not compatible with forecast_step for all plotted data; "
+                "using forecast_step as x-axis."
+            )
+            time_dim = "forecast_step"
     return selected_data, time_dim