remove deprecation from math.round (#15224)

changelog.md

@@ -164,7 +164,14 @@
   echo foo
   ```
 
+- Proc `math.round` is no longer deprecated. The advice to use `strformat` instead
+  cannot be applied to every use case. The limitations and the (lack of) reliability
+  of `round` are well documented.
+
+
+
 ## Language changes
+
 - The `=destroy` hook no longer has to reset its target, as the compiler now automatically inserts
   `wasMoved` calls where needed.
 - In the newruntime it is now allowed to assign to the discriminator field