remove damage debug options

Now that we use wlr_scene, wlroots handles these. If available use
the wlroots debug options instead.

include/sway/server.h

@@ -156,13 +156,6 @@ struct sway_debug {
 	bool noatomic;         // Ignore atomic layout updates
 	bool txn_timings;      // Log verbose messages about transactions
 	bool txn_wait;         // Always wait for the timeout before applying
-	bool noscanout;        // Disable direct scan-out
-
-	enum {
-		DAMAGE_DEFAULT,    // Default behaviour
-		DAMAGE_HIGHLIGHT,  // Highlight regions of the screen being damaged
-		DAMAGE_RERENDER,   // Render the full output when any damage occurs
-	} damage;
 };
 
 extern struct sway_debug debug;