Move project extension properties to an ext { } block in buildscript.

build.gradle

@@ -1,6 +1,11 @@
 import io.spring.gradle.convention.Utils
 
 buildscript {
+	ext {
+		snapshotBuild = Utils.isSnapshot(project)
+		milestoneBuild = Utils.isMilestone(project)
+		releaseBuild = Utils.isRelease(project)
+	}
 	repositories {
 		mavenCentral()
 		gradlePluginPortal()
@@ -47,7 +52,3 @@ description = 'Spring Boot for Apache Geode'
 //ext['spring-framework.version'] = "$springVersion"
 //ext['spring-data-bom.version'] = "$springDataBomVersion"
 //ext['spring-session-bom.version'] = "$springSessionBomVersion"
-
-ext.snapshotBuild = Utils.isSnapshot(project)
-ext.milestoneBuild = Utils.isMilestone(project)
-ext.releaseBuild = Utils.isRelease(project)