Reduce Lettuce shutdown timeout to 100ms

Reducing the default to 100ms is a good compromise to retain a quiet time
in for parallel execution and optimize for default, single-threaded
execution (such as test execution or regular application shutdown). The
shutdown timeout can be adjusted to fit specific application needs.

See gh-9526

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/redis/RedisProperties.java

@@ -316,7 +316,7 @@ public class RedisProperties {
 		/**
 		 * Shutdown timeout in milliseconds.
 		 */
-		private int shutdownTimeout = 2000;
+		private int shutdownTimeout = 100;
 
 		/**
 		 * Lettuce pool configuration.