publish: fix wrong maven url and bump to 0.3.0

Author: kezhenxu94

chatgpt-java-sdk/build.gradle

@@ -29,7 +29,7 @@ publishing {
     repositories {
         maven {
             name = "OSSRH"
-            url = "https://s01.oss.sonatype.org/service/local/staging/deploy/maven2"
+            url = "https://oss.sonatype.org/service/local/staging/deploy/maven2"
             credentials {
                 username = System.getenv("MAVEN_USERNAME")
                 password = System.getenv("MAVEN_PASSWORD")