Update dependency ch.qos.logback:logback-classic to v1.5.26 (#55)

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

Author: renovate[bot]

backend/gradle/libs.versions.toml

@@ -12,7 +12,7 @@ kotlinter = "5.4.0"
 kotlinx_coroutines = "1.10.2"
 kotlinx_serialization = "1.10.0"
 ktor = "3.4.0"
-logback = "1.5.25"
+logback = "1.5.26"
 prometheus = "1.16.2"
 serialization = "2.3.0"
 release = "3.1.0"