Refactor cHeadersDirectory path usage in KlangPlugin

Adjusted the usage of cHeadersDirectory in KlangPlugin's unpackCHeaderTask function by removing 'this' references. An 'mkdirs()' function call was added to ensure the directory exists before passing headers into it.

klang/gradle-plugin/src/main/kotlin/io/ygdrasil/KlangPlugin.kt

@@ -203,9 +203,10 @@ class KlangPlugin : Plugin<Project> {
 	}
 
 	private fun Project.unpackCHeaderTask(): Task = task("unpackCHeader") { task ->
-		task.onlyIf { this.cHeadersDirectory.doesNotExists() || this.cHeadersDirectory.isDirectoryEmpty() }
+		task.onlyIf { cHeadersDirectory.doesNotExists() || cHeadersDirectory.isDirectoryEmpty() }
 		task.doFirst {
-			this.cHeadersDirectory.deleteRecursively()
+			cHeadersDirectory.deleteRecursively()
+			cHeadersDirectory.mkdirs()
 			HeaderManager.putPlatformHeaderAt(cHeadersDirectory.toPath())
 		}
 	}