Upgrade to Spring Framework 6.1.0-M1

Closes gh-35977
Closes gh-35980

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/build.gradle

@@ -14,6 +14,11 @@ configurations.all {
 			if (dependency.requested.group.startsWith("com.fasterxml.jackson")) {
 				dependency.useVersion("2.14.2")
 			}
+			// Downgrade Spring Framework as Gradle cannot cope with 6.1.0-M1's
+			// multi-version jar files with bytecode in META-INF/versions/21
+			if (dependency.requested.group.equals("org.springframework")) {
+				dependency.useVersion("6.0.10")
+			}
 		}
 	}
 }