Bump org.springframework.security:spring-security-bom in /spring

Bumps [org.springframework.security:spring-security-bom](https://github.com/spring-projects/spring-security) from 6.5.5 to 6.5.6.
- [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@6.5.5...6.5.6)

---
updated-dependencies:
- dependency-name: org.springframework.security:spring-security-bom
  dependency-version: 6.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

spring/pom.xml

@@ -107,7 +107,7 @@
         <jdk>[17,)</jdk>
       </activation>
       <properties>
-        <spring.security.version>6.5.5</spring.security.version>
+        <spring.security.version>6.5.6</spring.security.version>
       </properties>
     </profile>
   </profiles>