Bump springBootVersion from 2.6.5 to 2.6.6

Bumps `springBootVersion` from 2.6.5 to 2.6.6.

Updates `spring-boot-gradle-plugin` 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)

Updates `spring-boot-dependencies` 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:spring-boot-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-dependencies
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

build.gradle

@@ -17,7 +17,7 @@
 buildscript {
     ext{
         //Plugins
-        springBootVersion = '2.6.5'
+        springBootVersion = '2.6.6'
         sonarqubeVersion = '3.3'
         asciidoctorGradleVersion = '1.6.1'
         artifactoryVersion = '4.28.1'