Bump org.asciidoctor:asciidoctorj-diagram from 2.3.0 to 2.3.1

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] <support@github.com>

Author: dependabot[bot]

pom.xml

@@ -83,7 +83,7 @@
     <build-helper-maven-plugin.version>3.4.0</build-helper-maven-plugin.version>
     <asciidoctor.maven.plugin.version>3.0.0</asciidoctor.maven.plugin.version>
     <asciidoctorj.version>2.5.13</asciidoctorj.version>
-    <asciidoctorj.diagram.version>2.3.0</asciidoctorj.diagram.version>
+    <asciidoctorj.diagram.version>2.3.1</asciidoctorj.diagram.version>
     <buildnumber.plugin.version>3.2.0</buildnumber.plugin.version>
     <jmh.version>1.37</jmh.version>
     <spotless.version>2.43.0</spotless.version>