Update org.cyclonedx.bom version in docs to 2.3.0

[mhalbritter]

https://github.com/CycloneDX/cyclonedx-gradle-plugin/releases/tag/cyclonedx-gradle-plugin-2.3.0

[mhalbritter]

Please also update src/docs/antora/modules/how-to/pages/build.adoc.