Mark Loom 1.4 as deprecated

Author: shedaniel

src/main/java/net/fabricmc/loom/util/Constants.java

@@ -29,7 +29,7 @@
 public class Constants {
 	public static final String PLUGIN_ID = "dev.architectury.loom";
 	public static final boolean PLUGIN_BETA = false;
-	public static final boolean PLUGIN_DEPRECATED = false;
+	public static final boolean PLUGIN_DEPRECATED = true;
 	public static final String LIBRARIES_BASE = "https://libraries.minecraft.net/";
 	public static final String RESOURCES_BASE = "https://resources.download.minecraft.net/";
 	public static final String VERSION_MANIFESTS = "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json";