Revert error coloring (for development on dedicated branch) (#565)

pkl-gradle/pkl-gradle.gradle.kts

@@ -87,12 +87,6 @@ gradlePluginTests {
   skippedGradleVersions = listOf()
 }
 
-tasks.withType<Test>().configureEach {
-  // Disable colour output in tests
-  // Need additional disablement here because of how Jansi is packaged in the plugin
-  systemProperty("org.pkl.thirdparty.jansiAnsi.disable", "true")
-}
-
 signing {
   publishing.publications.withType(MavenPublication::class.java).configureEach {
     if (name != "library") {