eliminate the dependency on the generated-docs repository

- add and register Antora Collector
- configure Antora Collection at runtime using another extension

antora-playbook.yml

@@ -1,5 +1,7 @@
 antora:
   extensions:
+  - ./lib/antora/extensions/inject-collector-config.js
+  - '@antora/collector-extension'
   - ./lib/antora/extensions/version-fix.js
   - ./lib/antora/extensions/major-minor-segment.js
 runtime:
@@ -13,8 +15,6 @@ git:
   ensure_git_suffix: false
 content:
   sources:
-    - url: https://github.com/spring-io/spring-generated-docs
-      branches: 'spring-projects/spring-security/{main,5.{{6..9},{1..9}+({0..9})}.{x,+({0..9}?(-RC{1..9}))}}'
     - url: https://github.com/spring-projects/spring-security
       branches: [main, '5.{{6..9},{1..9}+({0..9})}.x']
       tags: '5.{{6..9},{1..9}+({0..9})}.+({0..9})?(-RC{1..9})'