Bump asciidoctorj-diagram from 2.2.3 to 2.2.4

Bumps [asciidoctorj-diagram](https://github.com/asciidoctor/asciidoctorj-diagram) from 2.2.3 to 2.2.4.
- [Release notes](https://github.com/asciidoctor/asciidoctorj-diagram/releases)
- [Commits](asciidoctor/asciidoctorj-diagram@v2.2.3...v2.2.4)

---
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>

jetty-documentation/pom.xml

@@ -20,7 +20,7 @@
           <dependency>
             <groupId>org.asciidoctor</groupId>
             <artifactId>asciidoctorj-diagram</artifactId>
-            <version>2.2.3</version>
+            <version>2.2.4</version>
           </dependency>
         </dependencies>
         <configuration>