qa: remove empty javadoc, update copyright

src/main/java/org/terasology/explosives/logic/ExplosionActionComponent.java

@@ -7,8 +7,6 @@
 import org.terasology.engine.logic.health.EngineDamageTypes;
 import org.terasology.gestalt.entitysystem.component.Component;
 
-/**
- */
 public class ExplosionActionComponent implements Component<ExplosionActionComponent> {
     public ActionTarget relativeTo = ActionTarget.Instigator;
     public int damageAmount = 1000;

src/main/java/org/terasology/explosives/logic/TunnelAction.java

@@ -1,18 +1,6 @@
-/*
- * Copyright 2020 MovingBlocks
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2029 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
 package org.terasology.explosives.logic;
 
 import org.joml.Vector3f;

src/main/java/org/terasology/explosives/logic/TunnelActionComponent.java

@@ -6,8 +6,6 @@
 import org.terasology.engine.logic.health.EngineDamageTypes;
 import org.terasology.gestalt.entitysystem.component.Component;
 
-/**
- */
 public class TunnelActionComponent implements Component<TunnelActionComponent> {
     /**
      * The most blocks that can be destroyed before the action ends (counts duplicates, so actually way lower)