Exclude the Spring Gradle docbook-reference-plugin from the Spring Build Conventions Gradle Plugins during reference documentation generation.

build.gradle

@@ -16,7 +16,9 @@ buildscript {
 		}
 	}
 	dependencies {
-		classpath 'io.spring.gradle:spring-build-conventions:0.0.38'
+		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"
 	}
 }