docstr: Sets last activation to linear.
code: def model_modifier(m):
      """Sets last activation to linear."""
      m.layers[-1].activation = tf.keras.activations.linear
      return m
  
imports: import inspect
  from functools import partial
  from typing import Any, List, Optional, Union
  import matplotlib.cm
  import matplotlib.pyplot
  import numpy
  import tensorflow
  import tensorflow_addons
  from PIL import Image
  from tensorflow import keras
  from tensorflow.keras.models import Model
  from tf_keras_vis.gradcam import Gradcam, GradcamPlusPlus
  from tf_keras_vis.utils import normalize
  from typeguard import check_argument_types, typechecked
  from chitra.import_utils import is_installed
  from .datagenerator import Dataset
label_desc: Use image node_id 3 for calling the InterpretModel obj's underlying member method code with example usage: obj.model_modifier(m) and returns: m