Switch to local Spring Build Conventions Gradle Plugins.

build.gradle

@@ -16,9 +16,6 @@ buildscript {
 		}
 	}
 	dependencies {
-		classpath('io.spring.gradle:spring-build-conventions:0.0.38') {
-			exclude group: "io.spring.gradle", module: "docbook-reference-plugin"
-		}
 		classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootVersion"
 	}
 }