doc: update developer notes for removal of MakeUnique

Author: fanquake

doc/developer-notes.md

@@ -595,11 +595,6 @@ Common misconceptions are clarified in those sections:
 
   - *Rationale*: This avoids memory and resource leaks, and ensures exception safety.
 
-- Use `MakeUnique()` to construct objects owned by `unique_ptr`s.
-
-  - *Rationale*: `MakeUnique` is concise and ensures exception safety in complex expressions.
-    `MakeUnique` is a temporary project local implementation of `std::make_unique` (C++14).
-
 C++ data structures
 --------------------