Bump org.springframework.boot from 3.2.2 to 3.2.8

Bumps org.springframework.boot from 3.2.2 to 3.2.8.

---
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>

samples/boot/build.gradle

@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '3.2.2'
+	id 'org.springframework.boot' version '3.2.8'
 	id 'io.spring.dependency-management'
 	id 'java'
 }