Bump asciidoctorj-pdf from 1.6.2 to 2.0.6

Bumps [asciidoctorj-pdf](https://github.com/asciidoctor/asciidoctorj-pdf) from 1.6.2 to 2.0.6.
- [Release notes](https://github.com/asciidoctor/asciidoctorj-pdf/releases)
- [Commits](asciidoctor/asciidoctorj-pdf@v1.6.2...v2.0.6)

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

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

pom.xml

@@ -201,7 +201,7 @@
       <id>pdfs</id>
       <properties>
         <asciidoctor.maven.plugin.version>2.2.2</asciidoctor.maven.plugin.version>
-        <asciidoctorj.pdf.version>1.6.2</asciidoctorj.pdf.version>
+        <asciidoctorj.pdf.version>2.0.6</asciidoctorj.pdf.version>
         <asciidoctorj.version>2.5.3</asciidoctorj.version>
         <jruby.version>9.3.4.0</jruby.version>
       </properties>