update dependency

Author: hauner

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 openapiparser = "2023.3-SNAPSHOT"
 
 [libraries]
-plugin-kotlin = "org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.0"
+plugin-kotlin = "org.jetbrains.kotlin:kotlin-gradle-plugin:1.8.22"
 plugin-checker = "org.checkerframework:checkerframework-gradle-plugin:0.6.29"
 plugin-outdated = "com.github.ben-manes:gradle-versions-plugin:0.46.0"
 checker = "org.checkerframework:checker:3.36.0"
@@ -26,6 +26,6 @@ mockk = "io.mockk:mockk:1.13.5"
 jackson = ["jackson-databind", "jackson-yaml"]
 
 [plugins]
-kotlin = { id = "org.jetbrains.kotlin.jvm", version = "1.9.0" }
+kotlin = { id = "org.jetbrains.kotlin.jvm", version = "1.8.22" }
 nexus = { id = "io.github.gradle-nexus.publish-plugin", version = "1.3.0" }
 jacoco = { id = "org.barfuin.gradle.jacocolog", version = "3.1.0" }