Add javadoc jars for all artifacts

[philwebb]

We can't currently deploy from GitHub actions due to:

          properties: [
            { name: 'typeId', value: 'javadoc-staging' },
            {
              name: 'failureMessage',
              value: "Missing: no javadoc jar found in folder '/io/spring/javaformat/spring-javaformat-formatter-eclipse-jdk8/0.0.42'"
            },
            {
              name: 'failureMessage',
              value: "Missing: no javadoc jar found in folder '/io/spring/javaformat/***.javaformat.eclipse.tests/0.0.42'"
            },
            {
              name: 'failureMessage',
              value: "Missing: no javadoc jar found in folder '/io/spring/javaformat/spring-javaformat-formatter-eclipse-jdk17/0.0.42'"
            }
          ]