Fix Spigot annotation mistakes

while some of these may of been true, they are extreme cases and cause
a ton of noise to plugin developers.

Use ApiStatus.Internal instead of Deprecated for actual internal API
that continues to have use (internally).

These do not help plugin developers if they bring moise noise than value.

paper-api/src/main/java/org/bukkit/entity/ZombieVillager.java

@@ -13,15 +13,15 @@ public interface ZombieVillager extends Zombie {
      * Sets the villager profession of this zombie.
      */
     @Override
-    void setVillagerProfession(@Nullable Villager.Profession profession);
+    void setVillagerProfession(@NotNull Villager.Profession profession); // Paper
 
     /**
      * Returns the villager profession of this zombie.
      *
-     * @return the profession or null
+     * @return the profession
      */
     @Override
-    @Nullable
+    @NotNull // Paper
     Villager.Profession getVillagerProfession();
 
     /**