add warnings to scheduled removal deprecations

src/main/java/com/falsepattern/lib/internal/Share.java

@@ -45,4 +45,8 @@ public final class Share {
             throw new RuntimeException(e);
         }
     }
+
+    public static void deprecatedWarning(Throwable stacktrace) {
+        LOG.warn("DEPRECATED API CALLED!", stacktrace);
+    }
 }

src/main/java/com/falsepattern/lib/updates/UpdateChecker.java

@@ -22,6 +22,7 @@ package com.falsepattern.lib.updates;
 
 import com.falsepattern.lib.DeprecationDetails;
 import com.falsepattern.lib.StableAPI;
+import com.falsepattern.lib.internal.Share;
 import com.falsepattern.lib.internal.impl.updates.UpdateCheckerImpl;
 
 import net.minecraft.util.IChatComponent;
@@ -124,6 +125,7 @@ public final class UpdateChecker {
     @DeprecationDetails.RemovedInVersion("0.13")
     @StableAPI.Expose
     public static List<ModUpdateInfo> fetchUpdates(String url) throws UpdateCheckException {
+        Share.deprecatedWarning(new Throwable());
         return UpdateCheckerImpl.fetchUpdates(url);
     }
 
@@ -136,6 +138,7 @@ public final class UpdateChecker {
                         replacement = "fetchUpdatesAsyncV2")
     @DeprecationDetails.RemovedInVersion("0.13")
     public static CompletableFuture<List<ModUpdateInfo>> fetchUpdatesAsync(String url) {
+        Share.deprecatedWarning(new Throwable());
         return UpdateCheckerImpl.fetchUpdatesAsync(url);
     }
     //endregion