Fix predictable temp directory in Artemis embedded configuration

Update ArtemisEmbeddedConfigurationFactory to use ApplicationTemp for
generating the Artemis data directory. This ensures the path is securely
generated rather than using a predictable, hardcoded string.

Fixes gh-50743

Author: snicoll

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jms/artemis/ArtemisEmbeddedConfigurationFactory.java

@@ -16,8 +16,6 @@
 
 package org.springframework.boot.autoconfigure.jms.artemis;
 
-import java.io.File;
-
 import org.apache.activemq.artemis.api.core.QueueConfiguration;
 import org.apache.activemq.artemis.api.core.RoutingType;
 import org.apache.activemq.artemis.api.core.SimpleString;
@@ -31,6 +29,8 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.boot.system.ApplicationTemp;
+
 /**
  * Configuration used to create the embedded Artemis server.
  *
@@ -84,8 +84,7 @@ private String getDataDir() {
 		if (this.properties.getDataDirectory() != null) {
 			return this.properties.getDataDirectory();
 		}
-		String tempDirectory = System.getProperty("java.io.tmpdir");
-		return new File(tempDirectory, "artemis-data").getAbsolutePath();
+		return new ApplicationTemp().getDir("artemis-data").getAbsolutePath();
 	}
 
 }