feat(client): send X-Stainless-Kotlin-Version header

Author: stainless-app[bot]

finch-java-core/src/main/kotlin/com/tryfinch/api/core/ClientOptions.kt

@@ -490,6 +490,7 @@ private constructor(
             headers.put("X-Stainless-Package-Version", getPackageVersion())
             headers.put("X-Stainless-Runtime", "JRE")
             headers.put("X-Stainless-Runtime-Version", getJavaVersion())
+            headers.put("X-Stainless-Kotlin-Version", KotlinVersion.CURRENT.toString())
             headers.put("Finch-API-Version", "2020-09-17")
             clientId?.let { username ->
                 clientSecret?.let { password ->