Make compat a kwarg-only argument to Coordinates.merge.

Co-authored-by: Maximilian Roos <[email protected]>

Author: mjwillson

xarray/core/coordinates.py

@@ -541,6 +541,7 @@ def _merge_inplace(self, other, compat: CompatOptions | CombineKwargDefault):
     def merge(
         self,
         other: Mapping[Any, Any] | None,
+        *,
         compat: CompatOptions | CombineKwargDefault = "minimal",
     ) -> Dataset:
         """Merge two sets of coordinates to create a new Dataset