Prepare changelog for release

Author: Leonidas-from-XIV

CHANGES.md

@@ -1,21 +1,13 @@
-## unreleased
+## 2.1.2
 
-### Added
-
-### Changed
-
-### Deprecated
+*2023-11-23*
 
 ### Fixed
 
 - Fix the error location reported in the exception. Regression in 2.1.1
   (reported by @johnridesabike, regression test by @ElectreAAS, fix by
   @Leonidas-from-XIV, #171, #172)
 
-### Removed
-
-### Security
-
 ## 2.1.1
 
 *2023-10-10*