LibJS: Indent tests with 4 spaces instead of 2

Author: https://github.com/mattco98
Commit: 1ef573eb30
Pull-request: https://github.com/SerenityOS/serenity/pull/2689
Reviewed-by: https://github.com/linusg

Libraries/LibJS/Tests/classes/class-basic.js

@@ -1,5 +1,5 @@
 test("class properties", () => {
-  class A {}
-  expect(A.name).toBe("A");
-  expect(A).toHaveLength(0);
+    class A {}
+    expect(A.name).toBe("A");
+    expect(A).toHaveLength(0);
 });