remove license header

Author: alexcheng1982

src/main/java/com/javaaidev/springai/observability/otel/ToolCallingContentObservationFilter.java

@@ -1,19 +1,3 @@
-/*
- * Copyright 2023-2025 the original author or authors.
- *
- * 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
- *
- *      https://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.
- */
-
 package com.javaaidev.springai.observability.otel;
 
 import io.micrometer.common.KeyValue;