fix(deps): update dependency org.springframework.boot:spring-boot-starter-parent to v3.5.6

Author: renovate[bot]

backend/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
-    <version>3.5.5</version>
+    <version>3.5.6</version>
     <relativePath /> <!-- lookup parent from repository -->
   </parent>
   <groupId>ch.puzzle</groupId>

pom.xml

@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>3.5.5</version>
+		<version>3.5.6</version>
 		<relativePath/>
 	</parent>