Update boot 2.5.2

- Update gradle 6.8.3
- Handle other needed build changes

build.gradle

@@ -1,7 +1,7 @@
 buildscript {
 	ext {
 		log4jVersion = '1.2.17'
-		springBootVersion = '2.4.8'
+		springBootVersion = '2.5.2'
 		eclipsePersistenceVersion = '2.1.1'
 		kryoVersion = '4.0.2'
 		springCloudClusterVersion = '1.0.2.RELEASE'
@@ -481,9 +481,6 @@ configure(sampleProjects()) {
 		testCompile "org.hamcrest:hamcrest-library"
 		testCompile "junit:junit"
 	}
-	bootJar {
-		excludeDevtools = false
-	}
 	build.dependsOn bootJar
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists