Update kotlin monorepo to v2.0.21 (#263)

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

Author: renovate[bot]

gradle/libs.versions.toml

@@ -12,7 +12,7 @@ core_ktx = "1.13.1"
 detekt = "1.23.7"
 espresso_core = "3.6.1"
 junit = "4.13.2"
-kotlin = "2.0.20"
+kotlin = "2.0.21"
 min_sdk_version = "23"
 target_sdk_version = "34"
 benmanesversion = "0.51.0"