Upgrade asciidoctor-gradle-plugin to 4.0.5

Add remark not to replace Groovy DSL extension due to version constraints

Author: mrotteveel

build.gradle

@@ -20,7 +20,7 @@ plugins {
     id 'nu.studer.credentials' version '3.0'
     id 'maven-publish'
     id 'signing'
-    id 'org.asciidoctor.jvm.convert' version '4.0.4'
+    id 'org.asciidoctor.jvm.convert' version '4.0.5'
 }
 
 defaultTasks 'clean', 'build'
@@ -140,6 +140,7 @@ asciidoctorj {
     // NOTE: Don't upgrade to v 3.0.0, as it requires Java 11
     version = '2.5.13'
 
+    // NOTE: We can't use org.firebirdsql.asciidoctor:canonical-link:1.0 as it requires AsciidoctorJ 3.0.x and Java 17
     docExtensions file('doc-extension.groovy')
 }