chore(deps): Spring Boot example: Update to Spring Boot 3.4.4.

Change-Id: I6e6b08d6c87217da71ecc3d2ad9cdb12042f19c3
diff --git a/examples/spring-boot/pom.xml b/examples/spring-boot/pom.xml
index a4ea4eb..632206a 100644
--- a/examples/spring-boot/pom.xml
+++ b/examples/spring-boot/pom.xml
@@ -23,7 +23,7 @@
   <name>Quarkus Google Cloud JSON Logging Extension - Spring Boot Example</name>
 
   <properties>
-    <spring-boot.version>3.1.4</spring-boot.version>
+    <spring-boot.version>3.4.4</spring-boot.version>
   </properties>
 
   <dependencyManagement>