Upgrade Maven failsafe plugin to 2.21.0

See gh-12721

Author: philwebb

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -192,7 +192,7 @@
 		<maven-deploy-plugin.version>2.8.2</maven-deploy-plugin.version>
 		<maven-eclipse-plugin.version>2.10</maven-eclipse-plugin.version>
 		<maven-enforcer-plugin.version>3.0.0-M1</maven-enforcer-plugin.version>
-		<maven-failsafe-plugin.version>2.20.1</maven-failsafe-plugin.version>
+		<maven-failsafe-plugin.version>2.21.0</maven-failsafe-plugin.version>
 		<maven-install-plugin.version>2.5.2</maven-install-plugin.version>
 		<maven-invoker-plugin.version>3.0.0</maven-invoker-plugin.version>
 		<maven-help-plugin.version>2.2</maven-help-plugin.version>