Refactor code in numerical methods notebooks

- Updated import order in Point_Fixe.ipynb for consistency.
- Changed lambda functions to regular function definitions for clarity in Point_Fixe.ipynb.
- Added numpy import in TP1_EDO_EulerExp.ipynb, TP2_Lokta_Volterra.ipynb, and TP3_Convergence.ipynb for better readability.
- Modified for loops in TP1_EDO_EulerExp.ipynb and TP2_Lokta_Volterra.ipynb to include strict=False for compatibility with future Python versions.

M1/Numerical Methods/TP2.ipynb

@@ -38,10 +38,10 @@
    ],
    "source": [
     "import numpy as np\n",
-    "from sklearn.neural_network import MLPClassifier\n",
     "from sklearn.datasets import make_classification\n",
-    "from sklearn.model_selection import train_test_split\n",
     "from sklearn.metrics import accuracy_score\n",
+    "from sklearn.model_selection import train_test_split\n",
+    "from sklearn.neural_network import MLPClassifier\n",
     "\n",
     "accuracies = []\n",
     "\n",