build(deps): bump asciidoctorj-diagram from 2.1.2 to 2.2.1 (#316)

Bumps [asciidoctorj-diagram](https://github.com/asciidoctor/asciidoctorj-diagram) from 2.1.2 to 2.2.1.
- [Release notes](https://github.com/asciidoctor/asciidoctorj-diagram/releases)
- [Commits](asciidoctor/asciidoctorj-diagram@v2.1.2...v2.2.1)

---
updated-dependencies:
- dependency-name: org.asciidoctor:asciidoctorj-diagram
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

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

Author: dependabot[bot]

pom.xml

@@ -162,7 +162,7 @@
     <!-- Site properties -->
     <asciidoctor.maven.plugin.version>2.2.1</asciidoctor.maven.plugin.version>
     <asciidoctorj.version>2.5.3</asciidoctorj.version>
-    <asciidoctorj.diagram.version>2.1.2</asciidoctorj.diagram.version>
+    <asciidoctorj.diagram.version>2.2.1</asciidoctorj.diagram.version>
 
     <skip-code-generation-tests>true</skip-code-generation-tests>
     <skip-dependency-cve-scan>true</skip-dependency-cve-scan>