Bump @springio/antora-extensions from 1.14.7 to 1.14.9 in /docs

Bumps [@springio/antora-extensions](https://github.com/spring-io/antora-extensions) from 1.14.7 to 1.14.9.
- [Changelog](https://github.com/spring-io/antora-extensions/blob/main/CHANGELOG.adoc)
- [Commits](https://github.com/spring-io/antora-extensions/compare/v1.14.7...v1.14.9)

---
updated-dependencies:
- dependency-name: "@springio/antora-extensions"
  dependency-version: 1.14.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/package.json

@@ -4,7 +4,7 @@
     "@antora/atlas-extension": "1.0.0-alpha.5",
     "@antora/collector-extension": "1.0.2",
     "@asciidoctor/tabs": "1.0.0-beta.6",
-    "@springio/antora-extensions": "1.14.7",
+    "@springio/antora-extensions": "1.14.9",
     "@springio/asciidoctor-extensions": "1.0.0-alpha.17"
   }
 }