[ENH] `sklearn 1.7` compatibility

[fkiraly]

Multiple compatibility fixes with sklearn 1.7.

• The sklearn adapter was importing the private utility from sklearn, _deprecate_Xt_in_inverse_transform. This is fixed by removing the import and assuming the future interface.
• sklearn now has a more stringent set of input checks, instead of coercions. This is handled for the two estimators simultaneously - common methods are also moved ot a common adapter class.