Revert "add: accept authlib-injector artifact in current working directory"

This reverts commit 02cb2a3fb1.

HMCLCore/src/main/java/org/jackhuang/hmcl/auth/authlibinjector/AuthlibInjectorDownloader.java

@@ -127,10 +127,6 @@ public class AuthlibInjectorDownloader implements AuthlibInjectorArtifactProvide
         }
     }
 
-    public static boolean isArtifactsDirectory(Path artifactsDirectory) {
-        return Files.exists(artifactsDirectory.resolve("authlib-injector.jar"));
-    }
-
     private static class AuthlibInjectorVersionInfo {
         @SerializedName("build_number")
         public int buildNumber;