Polish "Upgrade Spring gRPC to 0.8.0"

See gh-1782

Author: mhalbritter

start-site/src/test/java/io/spring/start/site/extension/dependency/springgrpc/SpringGrpcProjectGenerationConfigurationTests.java

@@ -139,8 +139,8 @@ void shouldAddOsPluginForMaven() {
 	@Test
 	void shouldAddProtobufPluginForMaven() {
 		ProjectRequest request = createProjectRequest(SPRING_GRPC);
-		assertThat(mavenPom(request)).hasProperty("grpc.version", "1.70.0")
-			.hasProperty("protobuf-java.version", "3.25.6")
+		assertThat(mavenPom(request)).hasProperty("grpc.version", "1.72.0")
+			.hasProperty("protobuf-java.version", "4.30.2")
 			.containsIgnoringWhitespaces(
 					"""
 							<plugin>