Apply gradle plugin milestone version since views depends on it

Author: jdaugherty

gradle.properties

@@ -43,7 +43,7 @@ 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
-grails-gradle-plugin.version=7.0.0-SNAPSHOT
+grails-gradle-plugin.version=7.0.0-M2
 grails-testing-support.version=4.0.0-M2
 groovy.version=4.0.24
 gsp.version=7.0.0-M1