build(deps): bump ch.qos.logback:logback-classic

Bumps the test-dependencies group with 1 update in the / directory: [ch.qos.logback:logback-classic](https://github.com/qos-ch/logback).


Updates `ch.qos.logback:logback-classic` from 1.5.18 to 1.5.21
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](qos-ch/logback@v_1.5.18...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
  dependency-group: test-dependencies
...

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

Author: dependabot[bot]

build.gradle

@@ -187,7 +187,7 @@ testing {
                 implementation('org.mockito:mockito-core:5.20.0')
                 implementation('org.mockito:mockito-junit-jupiter:5.20.0')
                 implementation('com.github.stefanbirkner:system-lambda:1.2.1')
-                runtimeOnly('ch.qos.logback:logback-classic:1.5.18')
+                runtimeOnly('ch.qos.logback:logback-classic:1.5.21')
             }
         }
     }