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](qos-ch/logback@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] <[email protected]>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -5,7 +5,7 @@ commons-compress = "1.26.2"
 jackson = "2.20.1"
 jspecify = "1.0.0"
 jsr305 = "3.0.2"
-logback = "1.5.20"
+logback = "1.5.21"
 micrometer = "1.16.0"
 micrometer-docs-gen = "1.0.4"
 micrometer-tracing = "1.6.0"