Bump ch.qos.logback:logback-classic from 1.5.20 to 1.5.21

Bumps [ch.qos.logback:logback-classic](https://github.com/qos-ch/logback) from 1.5.20 to 1.5.21.
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](https://github.com/qos-ch/logback/compare/v_1.5.20...v_1.5.21)

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-classic
  dependency-version: 1.5.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

gradle/libs.versions.toml

@@ -17,7 +17,7 @@ org-opensaml5 = "5.1.2"
 org-springframework = "6.2.13"
 
 [libraries]
-ch-qos-logback-logback-classic = "ch.qos.logback:logback-classic:1.5.20"
+ch-qos-logback-logback-classic = "ch.qos.logback:logback-classic:1.5.21"
 com-fasterxml-jackson-jackson-bom = "com.fasterxml.jackson:jackson-bom:2.18.5"
 com-google-inject-guice = "com.google.inject:guice:3.0"
 com-netflix-nebula-nebula-project-plugin = "com.netflix.nebula:nebula-project-plugin:8.2.0"