Update Maven wrapper to 3.9.15 (Aliyun mirror)

Bump the Maven distribution used by the Maven wrapper from 3.9.14 to 3.9.15 by updating distributionUrl to the Aliyun mirror (https://maven.aliyun.com/...). wrapperVersion (3.3.4) and distributionType remain unchanged. This switches the download source and upgrades the Maven binary version for CI/local builds.

Author: mercyblitz

.mvn/wrapper/maven-wrapper.properties

@@ -1,3 +1,3 @@
 wrapperVersion=3.3.4
 distributionType=only-script
-distributionUrl=https://dlcdn.apache.org/maven/maven-3/3.9.14/binaries/apache-maven-3.9.14-bin.zip
+distributionUrl=https://maven.aliyun.com/repository/public/org/apache/maven/apache-maven/3.9.15/apache-maven-3.9.15-bin.zip