More @DirtiesContext in tests to mitigate memory

* Some other cleanups and modernizations for affected test class and their configurations

spring-integration-feed/src/test/java/org/springframework/integration/feed/inbound/FeedEntryMessageSourceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import java.net.HttpURLConnection;
 import java.net.URL;
 
 import com.rometools.rome.feed.synd.SyndEntry;
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -46,15 +47,24 @@ import static org.mockito.Mockito.mock;
  */
 public class FeedEntryMessageSourceTests {
 
+	static File metadataStoreFile;
+
 	@BeforeEach
 	public void prepare() {
-		File metadataStoreFile = new File(System.getProperty("java.io.tmpdir") + "/spring-integration/",
+		metadataStoreFile = new File(System.getProperty("java.io.tmpdir") + "/spring-integration/",
 				"metadata-store.properties");
 		if (metadataStoreFile.exists()) {
 			metadataStoreFile.delete();
 		}
 	}
 
+	@AfterAll
+	static void tearDown() {
+		if (metadataStoreFile.exists()) {
+			metadataStoreFile.delete();
+		}
+	}
+
 	@Test
 	public void testFailureWhenNotInitialized() throws Exception {
 		URL url = new ClassPathResource("org/springframework/integration/feed/sample.rss").getURL();