SpringBoot Docs artifact is deployed twice

The artifactory resource output shows the docs POM is uploaded twice.

When looking at the files in CI I see

find . | grep docs | grep pom$
./org/springframework/boot/spring-boot-docs/2.5.0-SNAPSHOT/spring-boot-docs-2.5.0-20210208.064833-2.pom
./org/springframework/boot/spring-boot-docs/2.5.0-SNAPSHOT/spring-boot-docs-2.5.0-20210208.064833-1.pom

I've raised https://github.com/spring-io/artifactory-resource/issues/74 to fix the issue, but we should probably work out why it's happening here.

Comment From: wilkinsona

I suspect this is specific to the Gradle-based build. The following in the logs is suspicious:

> Task :spring-boot-project:spring-boot-docs:publishMavenPublicationToDeploymentRepository
Multiple publications with coordinates 'org.springframework.boot:spring-boot-docs:2.3.9.BUILD-SNAPSHOT' are published to repository 'deployment'. The publications will overwrite each other!