doc: Fix unclosed code fence in src/manual/methods.md (#49357)

lucifer1004 · KristofferC · commit 1fb561eedd71 · 2023-10-11T11:26:14.000+02:00
(cherry picked from commit ff7b8eb)
diff --git a/doc/src/manual/methods.md b/doc/src/manual/methods.md
@@ -1247,5 +1247,6 @@ function f2(inc)
         x -> x - 1
     end
 end
+```
 
 [^Clarke61]: Arthur C. Clarke, *Profiles of the Future* (1961): Clarke's Third Law.
