spring-ws-docs does not enable snapshot or milestone repository if necessary

[snicoll]

I've tried to move to Spring Framework snapshots and the build fails as follows:

* What went wrong:
Execution failed for task ':spring-ws-docs:javadoc'.
> Could not resolve all files for configuration ':spring-ws-docs:javadocClasspath'.
   > Could not find org.springframework:spring-framework-bom:6.2.4-SNAPSHOT.
     Searched in the following locations:
       - https://repo.maven.apache.org/maven2/org/springframework/spring-framework-bom/6.2.4-SNAPSHOT/maven-metadata.xml
       - https://repo.maven.apache.org/maven2/org/springframework/spring-framework-bom/6.2.4-SNAPSHOT/spring-framework-bom-6.2.4-SNAPSHOT.pom
     Required by:
         project :spring-ws-docs > project :spring-ws-platform
   > Could not find org.springframework:spring-oxm:.
     Required by:
         project :spring-ws-docs > project :spring-ws-core
   > Could not find org.springframework:spring-web:.
     Required by:
         project :spring-ws-docs > project :spring-ws-core
   > Could not find org.springframework:spring-webmvc:.
     Required by:
         project :spring-ws-docs > project :spring-ws-core
   > Could not find org.springframework:spring-tx:.
     Required by:
         project :spring-ws-docs > project :spring-ws-security
   > Could not find org.springframework:spring-jms:.
     Required by:
         project :spring-ws-docs > project :spring-ws-support