bump kotlin to 1.9.23 (#36735)

There's a bug fix in 1.19.23 that caused compilation to pass, and potentially tests to fail : https://youtrack.jetbrains.com/issue/KT-64640.
we're bumping kotlin to the latest version (which fixes that bug)and updating our code that was exploiting it
they also fixed https://youtrack.jetbrains.com/issue/KT-66044, which caused the List.getFirst() to be removed from the API, so we had to change that too

build.gradle

@@ -7,7 +7,7 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 plugins {
     id 'base'
     id 'com.github.spotbugs' version '6.0.7' apply false
-    id 'org.jetbrains.kotlin.jvm' version '1.9.22' apply false
+    id 'org.jetbrains.kotlin.jvm' version '1.9.23' apply false
 }
 
 allprojects {