Deploy spring-boot-test-support so it's available downstream

Concourse builds spring-boot-tests separately from spring-boot-project
and relies on modules from the latter being available in the
distribution repository when building the former. This commit enables the
deployment of spring-boot-test-support from spring-boot-project so that it
is added to the distribution repository and is therefore available when
building spring-boot-tests. It is then excluded when putting to the
Artifactory resource as we do not want it to be published.

See gh-15471

ci/pipeline.yml

@@ -191,6 +191,7 @@ jobs:
       build_number: "${BUILD_PIPELINE_NAME}-${BUILD_JOB_NAME}-${BUILD_NAME}"
       disable_checksum_uploads: true
       exclude:
+      - "**/spring-boot-test-support/**"
       - "**/*.effective-pom"
       artifact_set:
       - include: