Update testing to Keras 3.11.2 because of Dependabot alert no. 82 / CVE-2025-8747

Signed-off-by: Beat Buesser <[email protected]>

Author: beat-buesser

.github/workflows/ci-legacy.yml

@@ -29,7 +29,7 @@ jobs:
       matrix:
         module: [attacks_1, attacks_2, estimators, defences, metrics, art]
         include:
-          - name: legacy (TensorFlow 2.18.1 Keras 3.10.0 PyTorch 2.7.0 scikit-learn 1.6.1 Python 3.10)
+          - name: legacy (TensorFlow 2.18.1 Keras 3.11.2 PyTorch 2.7.0 scikit-learn 1.6.1 Python 3.10)
             framework: legacy
             python: '3.10'
             tensorflow: 2.18.1