Fix typo

Co-authored-by: Naoki Kanazawa <[email protected]>

Author: itoko

qiskit_experiments/library/randomized_benchmarking/rb_utils.py

@@ -228,7 +228,7 @@ def coherence_limit_error(
             \end{bmatrix}
 
         The coherence limit error computed by this function is
-        :math:`1 - F_{\text{avg}}(\mathcal{E}, U)` and the following equalities hold for tha value.
+        :math:`1 - F_{\text{avg}}(\mathcal{E}, U)` and the following equalities hold for the value.
 
         .. math::