Prevent upgrade to AspectJ 1.9.8 as it requires Java 11

Author: snicoll

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -97,6 +97,9 @@ bom {
 		}
 	}
 	library("AspectJ", "1.9.7") {
+		prohibit("[1.9.8.M1,)") {
+			because "it requires Java 11"
+		}
 		group("org.aspectj") {
 			modules = [
 				"aspectjrt",