Revert "[maven-release-plugin] prepare for next development iteration"

This reverts commit 46eb8edb33d350637cf9df4d386a789c05a30a6a.
Revert "[maven-release-plugin] prepare release wiquery-parent-6.12.0"

This reverts commit 8687225333e386cb1d71f08ef1478aa39e9ac7a2.