Bump @springio/asciidoctor-extensions (#1705)

Bumps [@springio/asciidoctor-extensions](https:/spring-io/asciidoctor-extensions) from 1.0.0-alpha.10 to 1.0.0-alpha.13.
- [Changelog](https:/spring-io/asciidoctor-extensions/blob/main/CHANGELOG.adoc)
- [Commits](spring-io/asciidoctor-extensions@v1.0.0-alpha.10...v1.0.0-alpha.13)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -5,7 +5,7 @@
  "@antora/collector-extension": "1.0.0-alpha.3",
  "@asciidoctor/tabs": "1.0.0-beta.6",
  "@springio/antora-extensions": "1.11.1",
- "@springio/asciidoctor-extensions": "1.0.0-alpha.10",
+ "@springio/asciidoctor-extensions": "1.0.0-alpha.13",
  "asciidoctor-kroki": "0.18.1"
  }
 }