Fix QuartzAutoConfiguration when Liquibase is not on the class path

Fixes spring-projectsgh-18153

Author: wilkinsona

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

@@ -166,8 +166,8 @@ public QuartzDataSourceInitializer quartzDataSourceInitializer(DataSource dataSo
 
 		/**
 		 * Additional configuration to ensure that {@link SchedulerFactoryBean} and
-		 * {@link Scheduler} beans depend on the {@link QuartzDataSourceInitializer}
-		 * bean(s).
+		 * {@link Scheduler} beans depend on any beans that perform data source
+		 * initialization.
 		 */
 		@Configuration
 		static class QuartzSchedulerDependencyConfiguration {
@@ -183,10 +183,16 @@ public static SchedulerDependsOnBeanFactoryPostProcessor quartzSchedulerFlywayDe
 				return new SchedulerDependsOnBeanFactoryPostProcessor(FlywayMigrationInitializer.class);
 			}
 
-			@Bean
-			@ConditionalOnBean(SpringLiquibase.class)
-			public static SchedulerDependsOnBeanFactoryPostProcessor quartzSchedulerLiquibaseDependsOnBeanFactoryPostProcessor() {
-				return new SchedulerDependsOnBeanFactoryPostProcessor(SpringLiquibase.class);
+			@Configuration
+			@ConditionalOnClass(SpringLiquibase.class)
+			static class LiquibaseQuartzSchedulerDependencyConfiguration {
+
+				@Bean
+				@ConditionalOnBean(SpringLiquibase.class)
+				public static SchedulerDependsOnBeanFactoryPostProcessor quartzSchedulerLiquibaseDependsOnBeanFactoryPostProcessor() {
+					return new SchedulerDependsOnBeanFactoryPostProcessor(SpringLiquibase.class);
+				}
+
 			}
 
 		}