Revert "Fix dependency management failure"

This reverts commit 1ef3d3bda9680b4c4517ef0a32a91250e15c2be8.
Remove spring-data release train BOM

Temporarily remove the spring-data release train BOM since it cannot
be resolved until it is published to maven central.

The previous solution of adding an additional repository has been
reverted as it will pollute POMS for users that inherit from the
spring-boot-starter-parent POM.