[skip ci] pre release for grails-data-mapping

Author: jdaugherty

gradle.properties

@@ -39,7 +39,7 @@ directory-watcher.version=0.18.0
 flying-saucer-pdf-openpdf.version=9.4.0
 geb-spock.version=7.0
 grails-async.version=6.0.0-M2
-grails-datastore.version=9.0.0-SNAPSHOT
+grails-datastore.version=9.0.0-M2
 grails-datastore-gorm-hibernate5.version=9.0.0-SNAPSHOT
 grails-datastore-gorm-mongodb.version=9.0.0-SNAPSHOT
 grails-gdoc-engine.version=1.0.1