chore(deps): bump org.asciidoctor:asciidoctorj-pdf from 2.3.20 to 2.3.21

Bumps [org.asciidoctor:asciidoctorj-pdf](https://github.com/asciidoctor/asciidoctorj-pdf) from 2.3.20 to 2.3.21.
- [Release notes](https://github.com/asciidoctor/asciidoctorj-pdf/releases)
- [Changelog](https://github.com/asciidoctor/asciidoctorj-pdf/blob/main/CHANGELOG.adoc)
- [Commits](asciidoctor/asciidoctorj-pdf@v2.3.20...v2.3.21)

---
updated-dependencies:
- dependency-name: org.asciidoctor:asciidoctorj-pdf
  dependency-version: 2.3.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

fj-doc-guide/pom.xml

@@ -24,7 +24,7 @@
 	<properties>
 		<!-- asciidoc properties -->
 		<asciidoctor.maven.plugin.version>3.2.0</asciidoctor.maven.plugin.version>
-		<asciidoctorj.pdf.version>2.3.20</asciidoctorj.pdf.version>
+		<asciidoctorj.pdf.version>2.3.21</asciidoctorj.pdf.version>
 		<asciidoctorj.version>3.0.0</asciidoctorj.version>
 		<asciidoctorj.diagram.version>3.0.1</asciidoctorj.diagram.version>
 		<asciidoctorj.diagram-plantuml.version>1.2025.3</asciidoctorj.diagram-plantuml.version>

fj-doc-playground-quarkus/pom.xml

@@ -322,7 +322,7 @@
 			<properties>
 				<!-- asciidoc properties -->
 				<asciidoctor.maven.plugin.version>3.2.0</asciidoctor.maven.plugin.version>
-				<asciidoctorj.pdf.version>2.3.20</asciidoctorj.pdf.version>
+				<asciidoctorj.pdf.version>2.3.21</asciidoctorj.pdf.version>
 				<asciidoctorj.version>3.0.0</asciidoctorj.version>
 				<asciidoctorj.diagram.version>3.0.1</asciidoctorj.diagram.version>
 				<asciidoctorj.diagram-plantuml.version>1.2025.3</asciidoctorj.diagram-plantuml.version>