fix(workspace): use public static overload of traverseForMvnw

The 2-arg traverseForMvnw is a private instance method on
JavaMavenProvider. Call the 3-arg public static overload with null
repoRoot instead, which has the same behavior.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Strum355

src/main/java/io/github/guacsec/trustifyda/impl/ExhortApi.java

@@ -959,7 +959,7 @@ private static String resolveGradleBinary(Path startDir) {
       String wrapperName = Operations.isWindows() ? "gradlew.bat" : "gradlew";
       String wrapper =
           JavaMavenProvider.traverseForMvnw(
-              wrapperName, startDir.resolve("build.gradle").toString());
+              wrapperName, startDir.resolve("build.gradle").toString(), null);
       if (wrapper != null) {
         return wrapper;
       }