Stop logger context so that file handlers are not leaked

See gh-47424

Author: wilkinsona

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/Log4J2LoggingSystemTests.java

@@ -37,6 +37,7 @@
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.config.LoggerConfig;
+import org.apache.logging.log4j.core.config.Reconfigurable;
 import org.apache.logging.log4j.core.config.composite.CompositeConfiguration;
 import org.apache.logging.log4j.core.config.plugins.util.PluginRegistry;
 import org.apache.logging.log4j.core.config.xml.XmlConfiguration;
@@ -114,6 +115,15 @@ void setup(TestInfo testInfo) {
 	@AfterEach
 	void cleanUp() {
 		this.loggingSystem.cleanUp();
+		LoggerContext loggerContext = (LoggerContext) LogManager.getContext(false);
+		Configuration configuration = loggerContext.getConfiguration();
+		loggerContext.stop();
+		if (configuration instanceof Reconfigurable reconfigurable) {
+			loggerContext.start(reconfigurable.reconfigure());
+		}
+		else {
+			loggerContext.start(configuration);
+		}
 		PluginRegistry.getInstance().clear();
 	}