Bump both kotlin versions at the same time. (#412)

Author: runningcode

android/gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 agp = "8.9.1"
-kotlin = "2.1.10"
-ksp = "2.1.10-1.0.31"
+kotlin = "2.1.20"
+ksp = "2.1.20-1.0.31"
 coreKtx = "1.15.0"
 junit = "4.13.2"
 junitVersion = "1.1.5" # This is to match Compose's version