add version 2.40 to debian/changelog

Author: jendrikseipp

debian/changelog

@@ -1,3 +1,12 @@
+rednotebook (2.40-1) UNRELEASED; urgency=low
+
+  * New upstream release
+  * Fix black WebKit panes on KDE by disabling compositing on this platform (#828, @jendrikseipp).
+  * Fix empty WebKit preview with Nvidia drivers by auto-applying DMA-BUF workaround (#820, @jendrikseipp).
+  * Only instantiate Gtk.StatusIcon on Windows to fix Wayland crash (#840, @jendrikseipp).
+
+ -- Jendrik Seipp <[email protected]>  Tue, 26 Aug 2025 19:55:05 +0200
+
 rednotebook (2.39-1) UNRELEASED; urgency=low
 
   * New upstream release