Add go release versions to client_matrix.py
diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index f32bdf8..71d3a79 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -101,7 +101,7 @@
             'v1.7.4': None
         },
         {
-            'v1.8.1': None
+            'v1.8.2': None
         },
     ],
     'java': [