Update logback monorepo to v1.5.15 (#61)

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

Author: renovate[bot]

build.gradle.kts

@@ -16,8 +16,8 @@ dependencies {
     implementation("com.apptasticsoftware:rssreader:3.9.1")
     implementation("org.apache.commons:commons-text:1.13.0")
     implementation("com.github.Carleslc.Simple-YAML:Simple-Yaml:1.8.4")
-    implementation("ch.qos.logback:logback-classic:1.5.12")
-    compileOnly("ch.qos.logback:logback-core:1.5.12")
+    implementation("ch.qos.logback:logback-classic:1.5.15")
+    compileOnly("ch.qos.logback:logback-core:1.5.15")
     compileOnly("org.slf4j:slf4j-api:2.0.16")
 }