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

This reverts commit 432606162d4ea660831d3799a8195c00af4619aa.
Revert "[maven-release-plugin] prepare release 6.2.0-ga1"

This reverts commit ad732586b42476ffe3d58fc8addd5d4e58c87a2c.
Revert "Prepare 6.2.0-ga1 release."

This reverts commit 19fece444eca4efdb9a1f3ce66617d34a4482f0c.