Preserve last modified in copy actions in Gradle without using ant.copy task.

preserve-last-modified.build.gradle.kts

// From https://github.com/gradle/kotlin-dsl/blob/70aca202558f2f6e43cd8ead3ec95d669bfd7b33/build.gradle.kts#L69
// Preserve file modified dates without using ant.copy task
val copyCurrentDistro by task<Copy> {
	description = "Copies the current Gradle distro into '$customInstallationDir'."

	from(gradle.gradleHomeDir)
	into(customInstallationDir)
	exclude("**/*kotlin*")

	// preserve last modified date on each file to make it easier
	// to check which files were patched by next step
	val copyDetails = mutableListOf<FileCopyDetails>()
	eachFile { copyDetails.add(this) }
	doLast {
		copyDetails.forEach { details ->
			File(customInstallationDir, details.path).setLastModified(details.lastModified)
		}
	}

	// don't bother recreating it
	onlyIf { !customInstallationDir.exists() }
}