increment version number to 0.23.15

NEWS

+ver 0.23.15 (not yet released)
+
 ver 0.23.14 (2023/10/08)
 * decoder
   - flac: fix scanning files with non-ASCII names on Windows

android/AndroidManifest.xml

@@ -2,8 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="org.musicpd"
           android:installLocation="auto"
-          android:versionCode="72"
-          android:versionName="0.23.14">
+          android:versionCode="73"
+          android:versionName="0.23.15">
 
   <uses-sdk android:minSdkVersion="24" android:targetSdkVersion="30"/>
 

meson.build

 project(
   'mpd',
   ['c', 'cpp'],
-  version: '0.23.14',
+  version: '0.23.15',
   meson_version: '>= 0.56.0',
   default_options: [
     'c_std=c11',