Revert to Kotlin 1.8.10

The `ScriptsTests.testKotlinScript()` fail with:
```
Caused by: javax.script.ScriptException: error: cannot access 'java.io.Serializable' which is a supertype of 'kotlin.Int'. Check your module classpath for missing or conflicting dependencies
2 + bindings["payload"] as Int
  ^

	at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.asJsr223EvalResult(KotlinJsr223JvmScriptEngineBase.kt:104)
	at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.compileAndEval(KotlinJsr223JvmScriptEngineBase.kt:63)
	at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.eval(KotlinJsr223JvmScriptEngineBase.kt:31)
	at java.scripting/javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:231)
	at org.springframework.integration.scripting.jsr223.AbstractScriptExecutor.executeScript(AbstractScriptExecutor.java:84)
```

Author: artembilan

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlinVersion = '1.8.20'
+    ext.kotlinVersion = '1.8.10'
     ext.isCI = System.getenv('GITHUB_ACTION') || System.getenv('bamboo_buildKey')
     repositories {
         gradlePluginPortal()