Fix typo in KQD learning page (#4137)

Fixes #4136

Author: micpap25

learning/courses/quantum-diagonalization-algorithms/krylov.ipynb

@@ -811,7 +811,7 @@
     "abserr = 0.05\n",
     "accept_subspace_size = []\n",
     "\n",
-    "# Lists to store total time spent on the Krylov method, and he the subset of that time spent on diagonalizing the projected matrix.\n",
+    "# Lists to store total time spent on the Krylov method, and the subset of that time spent on diagonalizing the projected matrix.\n",
     "matrix_krylov_tot_times = []\n",
     "matrix_krylov_dim = []\n",
     "\n",