fix: update license information in convert-mysql-to-postgresql.py

Author: Fábio Luciano

grafana/scripts/convert-mysql-to-postgresql.py

@@ -1,4 +1,19 @@
 #!/usr/bin/env python3
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+
 """
 Convert Grafana dashboards from MySQL to PostgreSQL datasource.
 Uses sqlglot for AST-based SQL parsing and transformation.