Fix lazy modelcontext import flagged by ruff

Author: aman-coder03

pymc/distributions/shape_utils.py

@@ -33,7 +33,7 @@
 from pytensor.tensor.type_other import NoneTypeT
 from pytensor.tensor.variable import TensorVariable
 
-#from pymc.model import modelcontext
+# from pymc.model import modelcontext
 from pymc.pytensorf import convert_observed_data
 
 __all__ = [
@@ -415,6 +415,8 @@ def get_support_shape(
         assert isinstance(dims, tuple)
         if len(dims) < ndim_supp:
             raise ValueError(f"Number of dims is too small for ndim_supp of {ndim_supp}")
+        from pymc.model.core import modelcontext
+
         model = modelcontext(None)
         inferred_support_shape = [
             model.dim_lengths[dims[i]] - support_shape_offset[i] for i in range(-ndim_supp, 0)