deps: update dependency ch.qos.logback:logback-classic to v1.5.21

Author: renovate[bot]

gradle/libs.versions.toml

@@ -8,7 +8,7 @@ shadowPlugin = "9.2.2"
 kotest = "6.0.4"
 log4jApi = "2.25.2"
 log4jApiKotlin = "1.5.0"
-logback = "1.5.20"
+logback = "1.5.21"
 
 [plugins]
 detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detektPlugin" }