MLIA-569 Update TensorFlow to version 2.8

- Update TensorFlow to version 2.8 (now supported by Vela 3.4)
- Adapt existing codebase to preserve intermediary tensors in the interpreter in order to avoid errors when trying to print all of them in the future.
- Ignore types for numpy methods that do not have typing annotations in their definitions. This is needed because otherwise mypy would consider the calling function to also be untyped.

Change-Id: I943ac196fd4e378f5238949b15c23a2d628c8b5e

1 files changed, 4 insertions, 1 deletions

diff --git a/src/mlia/nn/tensorflow/optimizations/pruning.py b/src/mlia/nn/tensorflow/optimizations/pruning.py
index f1e2976..15c043d 100644
--- a/src/mlia/nn/tensorflow/optimizations/pruning.py
+++ b/src/mlia/nn/tensorflow/optimizations/pruning.py
@@ -147,11 +147,14 @@ class Pruner(Optimizer):
                 nonzero_weights = np.count_nonzero(tf.keras.backend.get_value(weight))
                 all_weights = tf.keras.backend.get_value(weight).size
 
+                # Types need to be ignored for this function call because
+                # np.testing.assert_approx_equal does not have type annotation while the
+                # current context does.
                 np.testing.assert_approx_equal(
                     self.optimizer_configuration.optimization_target,
                     1 - nonzero_weights / all_weights,
                     significant=2,
-                )
+                )  # type: ignore
 
     def _strip_pruning(self) -> None:
         self.model = tfmot.sparsity.keras.strip_pruning(self.model)