Remove logback.xml from rest-client module

Client library JARs should not package logback.xml as it
overrides the logging configuration of consuming applications.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

rest-client/src/main/resources/logback.xml

@@ -1,34 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<!--
-
-    Copyright © 2016-2026 The Thingsboard 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
-
-        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.
-
--->
-<!DOCTYPE configuration>
-<configuration>
-
-    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
-        <encoder>
-            <pattern>%d{ISO8601} [%thread] %-5level %logger{36} - %msg%n</pattern>
-        </encoder>
-    </appender>
-
-    <logger name="org.thingsboard.server" level="INFO" />
-
-    <root level="INFO">
-        <appender-ref ref="STDOUT"/>
-    </root>
-
-</configuration>