Update Jupyter notebooks and improve HHL algorithm implementation

Author: vinayswamik

examples/QPE/qpe.ipynb

@@ -12,7 +12,7 @@
     "import sys\n",
     "import os\n",
     "\n",
-    "sys.path.insert(0, os.path.abspath(os.path.join(os.getcwd(), '..')))"
+    "sys.path.insert(0, os.path.abspath(os.path.join(os.getcwd(), \"..\")))"
    ]
   },
   {
@@ -116,7 +116,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },
@@ -130,7 +130,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.11"
+   "version": "3.13.2"
   }
  },
  "nbformat": 4,