material_shaders example broken

I would like to learn about shaders in Armory3D. The example `armory3d/armory_examples/tree/master/material_shaders` cannot be loaded in Blender. Error:

```
A node of type LNMathNode in tree "NodeTree" failed to be updated, because there is no (longer?) an update routine for this version of the node. Original exception:
Traceback (most recent call last):
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/replacement.py", line 237, in replace_all
replace(tree, node)
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/replacement.py", line 151, in replace
response = node.get_replacement_node(tree)
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/math/LN_math.py", line 136, in get_replacement_node
raise LookupError()
LookupError

A node of type LNMathNode in tree "NodeTree" failed to be updated, because there is no (longer?) an update routine for this version of the node. Original exception:
Traceback (most recent call last):
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/replacement.py", line 237, in replace_all
replace(tree, node)
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/replacement.py", line 151, in replace
response = node.get_replacement_node(tree)
File "/data1/ArmorySDK/armsdk/armory/blender/arm/logicnode/math/LN_math.py", line 136, in get_replacement_node
raise LookupError()
LookupError
```

I would attempt to update it so it works in latest Armory3D, but Blender crashes after it displays that error.

Using Armory3D 2024.2, Blender 3.6.9.

(Example created with 2022.12)

Start by reproducing the load failure with material_shaders using Armory3D 2024.2 and Blender 3.6.9. Read armory/blender/arm/logicnode/replacement.py and armory/blender/arm/logicnode/math/LN_math.py, especially the reported replacement path. Done means the example opens in the current versions without the LNMathNode error or Blender crash.

Written by the indexing model from the issue text.