Use package.json for antora package management

Issue gh-14819

build.gradle

@@ -4,19 +4,10 @@ plugins {
 }
 
 antora {
-	version = '3.2.0-alpha.2'
 	options = [clean: true, fetch: true, stacktrace: true]
 	environment = [
 		'ALGOLIA_API_KEY': '9d489079e5ec46dbb238909fee5c9c29',
 		'ALGOLIA_APP_ID': 'WB1FQYI187',
 		'ALGOLIA_INDEX_NAME': 'springdocs',
 	]
-	// NOTE remember to update the versions in lib/antora/templates/per-branch-antora-playbook.yml as well
-	dependencies = [
-		'@antora/atlas-extension': '1.0.0-alpha.1',
-		'@antora/collector-extension': '1.0.0-alpha.3',
-		'@asciidoctor/tabs': '1.0.0-beta.3',
-		'@springio/antora-extensions': '1.7.0',
-		'@springio/asciidoctor-extensions': '1.0.0-alpha.8',
-	]
 }

lib/antora/templates/per-branch-antora-playbook.yml

@@ -1,5 +1,3 @@
-# PACKAGES antora@3.2.0-alpha.2 @antora/atlas-extension:1.0.0-alpha.1 @antora/collector-extension@1.0.0-alpha.3 @springio/antora-extensions@1.1.0 @asciidoctor/tabs@1.0.0-beta.3 @opendevise/antora-release-line-extension@1.0.0
-#
 # The purpose of this Antora playbook is to build the docs in the current branch.
 antora:
   extensions:

package.json

@@ -0,0 +1,10 @@
+{
+  "dependencies": {
+    "antora": "3.2.0-alpha.2",
+    "@antora/atlas-extension": "1.0.0-alpha.2",
+    "@antora/collector-extension": "1.0.0-alpha.3",
+    "@asciidoctor/tabs": "1.0.0-beta.6",
+    "@springio/antora-extensions": "1.8.2",
+    "@springio/asciidoctor-extensions": "1.0.0-alpha.10"
+  }
+}