Bump rust version on CI image

src/client.rs

@@ -1331,7 +1331,7 @@ where
                         self.buffer_describe(message).await?;
                     }
 
-                    // Execute2
+                    // Execute
                     // Execute a prepared statement prepared in `P` and bound in `B`.
                     'E' => {
                         self.extended_protocol_data_buffer