Upgrade the samples to Spring Boot 2.4.x

Closes gh-723

samples/rest-notes-spring-data-rest/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.9.RELEASE</version>
+		<version>2.4.7</version>
 		<relativePath />
 	</parent>
 
@@ -37,6 +37,17 @@
 			<scope>runtime</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.junit.vintage</groupId>
+			<artifactId>junit-vintage-engine</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.hamcrest</groupId>
+					<artifactId>hamcrest-core</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>