Bump org.springframework.security:spring-security-bom (#9036)

Bumps [org.springframework.security:spring-security-bom](https://github.com/spring-projects/spring-security) from 6.1.7 to 6.1.8.
- [Release notes](https://github.com/spring-projects/spring-security/releases)
- [Changelog](https://github.com/spring-projects/spring-security/blob/main/RELEASE.adoc)
- [Commits](spring-projects/spring-security@6.1.7...6.1.8)

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

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Author: dependabot[bot]

build.gradle

@@ -106,7 +106,7 @@ ext {
     springGraphqlVersion = '1.2.5'
     springKafkaVersion = '3.0.15'
     springRetryVersion = '2.0.5'
-    springSecurityVersion = '6.1.7'
+    springSecurityVersion = '6.1.8'
     springVersion = '6.0.18'
     springWsVersion = '4.0.10'
     testcontainersVersion = '1.19.7'