Drop manual isEditable copy in CraftSign

Signs no longer have a specific isEdiable state, the entire API in this
regard needs updating/deprecation. The boolean field is completely gone,
replaced by a uuid (which will need a new setEditingPlayer(UUID) method
on the Sign interface), and the current upstream implementation of
setEdiable simply flips the is_waxed state.

This patch is hence not needed as it neither allows editing (which will
be redone in a later patch) nor is required to copy the is_waxed boolean
flag as it lives in the signs compound tag and is covered by applyTo.

patches/server/0770-Dolphin-API.patch

@@ -1,45 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
-Date: Tue, 7 Dec 2021 19:34:23 -0500
-Subject: [PATCH] Dolphin API
-
-
-diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftDolphin.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftDolphin.java
-index 938e141f161acf5de5d3361382b514caea02c6fb..c1db88ceb65eb81c542171fc5465224ef613ce3b 100644
---- a/src/main/java/org/bukkit/craftbukkit/entity/CraftDolphin.java
-+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftDolphin.java
-@@ -24,4 +24,34 @@ public class CraftDolphin extends CraftWaterMob implements Dolphin {
-     public EntityType getType() {
-         return EntityType.DOLPHIN;
-     }
-+
-+    @Override
-+    public int getMoistness() {
-+        return this.getHandle().getMoistnessLevel();
-+    }
-+
-+    @Override
-+    public void setMoistness(int moistness) {
-+        this.getHandle().setMoisntessLevel(moistness);
-+    }
-+
-+    @Override
-+    public void setHasFish(boolean hasFish) {
-+        this.getHandle().setGotFish(hasFish);
-+    }
-+
-+    @Override
-+    public boolean hasFish() {
-+        return this.getHandle().gotFish();
-+    }
-+
-+    @Override
-+    public org.bukkit.Location getTreasureLocation() {
-+        return io.papermc.paper.util.MCUtil.toLocation(this.getHandle().level, this.getHandle().getTreasurePos());
-+    }
-+
-+    @Override
-+    public void setTreasureLocation(org.bukkit.Location location) {
-+        this.getHandle().setTreasurePos(io.papermc.paper.util.MCUtil.toBlockPosition(location));
-+    }
- }