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

This reverts commit 6d31fa0df9a5a4ed421fd1353ae5f9687f5ea0fd.
Revert "[maven-release-plugin] rollback the release of 1.9"

This reverts commit 5efa24655993e175a594e57e832d16fa1586923a.
Revert "[maven-release-plugin] prepare release 1.9"

This reverts commit 9d51bbc131bf3a3ea33d479dbe3bb1138f03aaf6.
Revert "[maven-release-plugin] rollback the release of sonar-l10n-es-plugin-1.9"

This reverts commit 5d081235bcca09be7072d56da9c6efdcf7addf0c.
Revert of the failed release because SNAPSHOT was used instead of the
release.