Revert "Upgrade to Kotlin 1.7, add -Xskip-metadata-version-check to buildSrc"

This reverts commit d24230099a.

buildSrc/build.gradle.kts

@@ -30,11 +30,4 @@ dependencies {
     preloadImplementation("org.openrndr:openrndr-extensions:$openrndrVersion")
 }
 
-tasks.getByName("compileKotlin").dependsOn("compilePreloadKotlin")
-
-// Here we deal with Gradle 7.4.2 using Kotlin 1.5 while OPENRNDR is compiled using Kotlin 1.7
-// This seems to work at this point in time but may cause serious problems in future scenarios in which either Kotlin,
-// Gradle or OPENRNDR are upgraded.
-tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
-    kotlinOptions.freeCompilerArgs = listOf("-Xskip-metadata-version-check")
-}
+tasks.getByName("compileKotlin").dependsOn("compilePreloadKotlin")