Bump the guide-dependencies-gradle group across 2 directories with 1 update

Bumps the guide-dependencies-gradle group with 1 update in the /complete directory: [org.springframework.boot](https://github.com/spring-projects/spring-boot).
Bumps the guide-dependencies-gradle group with 1 update in the /initial directory: [org.springframework.boot](https://github.com/spring-projects/spring-boot).


Updates `org.springframework.boot` from 4.0.8 to 4.0.9
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v4.0.8...v4.0.9)

Updates `org.springframework.boot` from 4.0.8 to 4.0.9
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v4.0.8...v4.0.9)

---
updated-dependencies:
- dependency-name: org.springframework.boot
  dependency-version: 4.0.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: guide-dependencies-gradle
- dependency-name: org.springframework.boot
  dependency-version: 4.0.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: guide-dependencies-gradle
...

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

Author: dependabot[bot]

complete/build.gradle

@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '4.0.8'
+	id 'org.springframework.boot' version '4.0.9'
 	id 'java'
 }
 

initial/build.gradle

@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '4.0.8'
+	id 'org.springframework.boot' version '4.0.9'
 	id 'java'
 }