Revert Kotlin to 2.2.21 for binary compatibility (#80)

Kotlin 2.3.0 introduced binary incompatibility that breaks downstream
consumers still on Kotlin 2.1.x (such as Square's invest service).

This reverts Kotlin from 2.3.0 back to 2.2.21 (commit 567058f).

Arrow 2.2.1 remains as it is compatible with Kotlin 2.2.21.

All tests pass with these versions.

Author: cjustice

gradle/libs.versions.toml

@@ -13,7 +13,7 @@ kfsm = "0.12.0"
 kotest = "5.9.1"
 kotestArrow = "2.0.0"
 # @pin
-kotlin = "2.3.0"
+kotlin = "2.2.21"
 kotlinBinaryCompatibilityPlugin = "0.18.1"
 kotlinLogging = "7.0.13"
 mavenPublish = "0.35.0"