Enable -Werror for buildSrc

buildSrc/build.gradle.kts

@@ -199,6 +199,7 @@ java {
 }
 
 tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions.allWarningsAsErrors = true
     kotlinOptions.freeCompilerArgs += listOf(
         "-Xopt-in=kotlin.RequiresOptIn",
         "-Xskip-runtime-version-check",
@@ -262,4 +263,4 @@ gradlePlugin {
             implementationClass = "org.jetbrains.kotlin.NativeInteropPlugin"
         }
     }
-}
+}