Release preparation

* bump release date
* remove revision suffix
* update NEWS.md

Author: dl8dtl

NEWS.md

@@ -1,4 +1,4 @@
-# Changes since AVR-LibC v2.2.0
+# Changes in AVR-LibC v2.3.0
 
 ## General
 

configure.ac

@@ -38,8 +38,8 @@ dnl        macro name           value            description
 m4_define([avr_libc_major],    [2])dnl           major version
 m4_define([avr_libc_minor],    [3])dnl           minor version
 m4_define([avr_libc_revision], [0])dnl           revision (dot-dot version)
-m4_define([avr_libc_revision_suffix], [git])dnl  revision suffix (if any)
-m4_define([avr_libc_reldate],  [20240609])dnl    release date
+m4_define([avr_libc_revision_suffix], [])dnl  revision suffix (if any)
+m4_define([avr_libc_reldate],  [20251223])dnl    release date
 dnl end of library versioning data
 
 m4_define([avr_libc_version],