Bump version number

Closes yshui#776

Signed-off-by: Yuxuan Shui <[email protected]>

Author: yshui

meson.build

@@ -1,4 +1,4 @@
-project('picom', 'c', version: '8',
+project('picom', 'c', version: '9',
         default_options: ['c_std=c11'])
 
 cc = meson.get_compiler('c')