Avoid dependency on pycuda in crazy

src/pystencils_reco/_crazy_decorator.py

@@ -26,7 +26,6 @@ def crazy(function) -> pystencils_reco.AssignmentCollection:
     # @disk_cache_no_fallback
     @functools.wraps(function)
     def wrapper(*args, **kwargs):
-        import pycuda.gpuarray  # TODO(seitz): remove dependency
         inspection = inspect.getfullargspec(function)
         arg_names = inspection.args
         annotations = inspection.annotations
@@ -35,7 +34,7 @@ def crazy(function) -> pystencils_reco.AssignmentCollection:
                         if is_array_like(a)
                         else a for i, a in enumerate(args)}
         compile_kwargs = {k: create_field_from_array_like(str(k), a, annotations.get(k, None))
-                          if (hasattr(a, '__array__') or isinstance(a, pycuda.gpuarray.GPUArray)) and
+                          if (hasattr(a, '__array__') or 'GPUArray' in str(a.__class__)) and
                           not isinstance(a, sympy.Matrix)  # noqa
                           else a for (k, a) in kwargs.items()}