Bump org.springframework.boot from 2.6.5 to 2.6.6

Bumps [org.springframework.boot](https://github.com/spring-projects/spring-boot) from 2.6.5 to 2.6.6.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.6.5...v2.6.6)

---
updated-dependencies:
- dependency-name: org.springframework.boot
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

build.gradle

@@ -1,7 +1,7 @@
 import org.apache.tools.ant.filters.ReplaceTokens
 
 plugins {
-    id 'org.springframework.boot' version '2.6.5'
+    id 'org.springframework.boot' version '2.6.6'
     id 'io.spring.dependency-management' version '1.0.11.RELEASE'
     id 'groovy'
     id 'application'