Fix dynamic axes for ONNX models (#1187)

(cherry picked from commit 53c0b37)

Author: RobertLucian

pkg/workloads/cortex/lib/client/onnx.py

@@ -111,8 +111,7 @@ def transform_to_numpy(input_pyobj, input_metadata, model_name):
 
     try:
         for idx, dim in enumerate(target_shape):
-            # dynamic_axes implies that a given dimension can have any size
-            if type(dim) is str and "dynamic_axes" in dim:
+            if type(dim) is str:
                 target_shape[idx] = -1
             elif type(dim) is not int:
                 target_shape[idx] = 1