Update dependency org.springframework.boot:spring-boot-starter-parent to v2.6.6

Author: renovate-bot

pom.xml

@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.6.5</version>
+		<version>2.6.6</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>