Update spring security to v5.8.7 (#931)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

gradle.properties

@@ -6,7 +6,7 @@ gorm.version=8.0.0
 vcsUrl=https://github.com/grails-plugins/grails-spring-security-core
 websiteUrl=https://github.com/grails-plugins/grails-spring-security-core
 issueTrackerUrl=https://github.com/grails-plugins/grails-spring-security-core/issues
-springSecurityVersion=5.8.6
+springSecurityVersion=5.8.7
 ehcacheVersion=2.10.9.2
 javaxServletApiVersion=4.0.1
 grailsTestingSupportVersion=3.0.0