switch to official Antora Plugin for Gradle

- lock version to latest release of Antora 3.1
- declare Node.js dependencies in build.gradle
- use Node.js version provided by plugin
- assign environment variables using environments property on extension block
- move group and description project properties to gradle.properties
- remove unneeded .npmrc
- upgrade to Gradle 7.5.1
- pass -q when running gradlew from Collector

antora-playbook.yml

@@ -4,9 +4,6 @@ antora:
   - '@antora/collector-extension'
   - ./lib/antora/extensions/version-fix.js
   - ./lib/antora/extensions/major-minor-segment.js
-runtime:
-  log:
-    format: pretty
 site:
   title: Spring Security
   url: https://docs.spring.io/spring-security/reference