Modernize Antora Build

- Use same playbook as docs-build
- Use Env Variables to cause partial build (same as docs-build)
- Use package.json so that dependencies can be updated with dependabot

framework-docs/framework-docs.gradle

@@ -10,27 +10,10 @@ apply from: "${rootDir}/gradle/publications.gradle"
 
 
 antora {
-	version = '3.2.0-alpha.2'
-	playbook = 'cached-antora-playbook.yml'
-	playbookProvider {
-		repository = 'spring-projects/spring-framework'
-		branch = 'docs-build'
-		path = 'lib/antora/templates/per-branch-antora-playbook.yml'
-		checkLocalBranch = true
-	}
-	options = ['--clean', '--stacktrace']
+	options = [clean: true, fetch: !project.gradle.startParameter.offline, stacktrace: true]
 	environment = [
-			'ALGOLIA_API_KEY': '82c7ead946afbac3cf98c32446154691',
-			'ALGOLIA_APP_ID': '244V8V9FGG',
-			'ALGOLIA_INDEX_NAME': 'framework-docs'
-	]
-	dependencies = [
-			'@antora/atlas-extension': '1.0.0-alpha.1',
-			'@antora/collector-extension': '1.0.0-alpha.3',
-			'@asciidoctor/tabs': '1.0.0-beta.3',
-			'@opendevise/antora-release-line-extension': '1.0.0-alpha.2',
-			'@springio/antora-extensions': '1.3.0',
-			'@springio/asciidoctor-extensions': '1.0.0-alpha.9'
+			'BUILD_REFNAME': 'HEAD',
+			'BUILD_VERSION': project.version,
 	]
 }