Arm backend: Convert assert to raise ValueError in op_clamp (#9932)

Asserts are converted to proper raises to ensure graph integrity.

It should not be possible for clamp to have more than 1 input for a
correctly formatted graph, but in the node visitor we cannot know for
sure that the graph is formatted correctly.

Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>

Author: Sebastian-Larsson

backends/arm/operators/op_clamp.py

@@ -63,7 +63,8 @@ def cast_type(value: Any) -> int | float:
                 # Attempt to cast to float
                 return float(value)
 
-        assert 2 <= len(node.args) <= 3
+        if len(node.args) != 2 and len(node.args) != 3:
+            raise ValueError(f"Expected len(node.args) to be 2 or 3, got {node.args}")
 
         min_arg = dtype_min
         max_arg = dtype_max
@@ -84,7 +85,10 @@ def define_node(
         inputs: List[TosaArg],
         output: TosaArg,
     ) -> None:
-        assert len(node.all_input_nodes) == 1
+        if len(node.all_input_nodes) != 1:
+            raise ValueError(
+                f"Expected 1 input for {self.target}, got {len(node.all_input_nodes)}"
+            )
 
         min_int8, max_int8 = self._get_min_max_arguments(
             node,
@@ -122,7 +126,10 @@ def define_node(
         inputs: List[TosaArg],
         output: TosaArg,
     ) -> None:
-        assert len(node.all_input_nodes) == 1
+        if len(node.all_input_nodes) != 1:
+            raise ValueError(
+                f"Expected 1 input for {self.target}, got {len(node.all_input_nodes)}"
+            )
 
         if inputs[0].dtype == ts.DType.INT8:
             # Call the inherited define_node for handling integers