Merge branch '2.6.x' into 2.7.x

Closes gh-33229

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/BackgroundPreinitializer.java

@@ -100,18 +100,22 @@ public class BackgroundPreinitializer implements ApplicationListener<SpringAppli
 				public void run() {
 					runSafely(new ConversionServiceInitializer());
 					runSafely(new ValidationInitializer());
-					runSafely(new MessageConverterInitializer());
-					runSafely(new JacksonInitializer());
+					if (!runSafely(new MessageConverterInitializer())) {
+						// If the MessageConverterInitializer we still might be able to
+						// initialize Jackson
+						runSafely(new JacksonInitializer());
+					}
 					runSafely(new CharsetInitializer());
 					preinitializationComplete.countDown();
 				}
 
-				public void runSafely(Runnable runnable) {
+				boolean runSafely(Runnable runnable) {
 					try {
 						runnable.run();
+						return true;
 					}
 					catch (Throwable ex) {
-						// Ignore
+						return false;
 					}
 				}