Merge pull request #507 from jhqwqmc/dev

添加paper依赖

bukkit/paper-loader/build.gradle.kts

@@ -116,6 +116,7 @@ paper {
         register("PxRpg") { required = false }
         register("Ratziel") { required = false }
         register("Reforges") { required = false }
+        register("Sertraline") { required = false }
         register("Slimefun") { required = false }
         register("StatTrackers") { required = false }
         register("SX-Item") { required = false }

core/src/main/java/net/momirealms/craftengine/core/plugin/context/ContextHolder.java

@@ -65,7 +65,7 @@ public class ContextHolder {
     }
 
     @SuppressWarnings("unchecked")
-    public <T> T getOrNull(ContextKey<T> parameter) {
+    public <T> @Nullable T getOrNull(ContextKey<T> parameter) {
         Supplier<Object> supplier = this.params.get(parameter);
         if (supplier == null) {
             return null;