Update kotlin monorepo to v2.3.20-RC (#1925)

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

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 jdkRelease = "17"
 minGradle = "9.0.0"
-kotlin = "2.3.20-Beta2"
+kotlin = "2.3.20-RC"
 moshi = "1.15.2"
 pluginPublish = "2.0.0"