Bump org.asciidoctor:asciidoctorj-diagram from 2.3.0 to 2.3.1 (#231)

Bumps [org.asciidoctor:asciidoctorj-diagram](https://github.com/asciidoctor/asciidoctorj-diagram) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/asciidoctor/asciidoctorj-diagram/releases)
- [Commits](asciidoctor/asciidoctorj-diagram@v2.3.0...v2.3.1)

---
updated-dependencies:
- dependency-name: org.asciidoctor:asciidoctorj-diagram
  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>

pom.xml

@@ -65,7 +65,7 @@
     <properties>
         <revision>1.38</revision>
         <asciidoctor.maven.plugin.version>3.0.0</asciidoctor.maven.plugin.version>
-        <asciidoctorj-diagram.version>2.3.0</asciidoctorj-diagram.version>
+        <asciidoctorj-diagram.version>2.3.1</asciidoctorj-diagram.version>
     </properties>
 
     <modules>