Upgrade to Maven Compiler Plugin 3.8.1

Closes gh-16802

Author: snicoll

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

@@ -218,7 +218,7 @@
 		<maven-antrun-plugin.version>1.8</maven-antrun-plugin.version>
 		<maven-assembly-plugin.version>3.1.1</maven-assembly-plugin.version>
 		<maven-clean-plugin.version>3.1.0</maven-clean-plugin.version>
-		<maven-compiler-plugin.version>3.8.0</maven-compiler-plugin.version>
+		<maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
 		<maven-dependency-plugin.version>3.1.1</maven-dependency-plugin.version>
 		<maven-deploy-plugin.version>2.8.2</maven-deploy-plugin.version>
 		<maven-enforcer-plugin.version>3.0.0-M2</maven-enforcer-plugin.version>