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/builtins/Date/Date.now.js

@@ -1,10 +1,10 @@
 test("basic functionality", () => {
-  var last = 0;
-  for (var i = 0; i < 100; ++i) {
-    var now = Date.now();
-    expect(now).not.toBeNaN();
-    expect(now).toBeGreaterThan(1580000000000);
-    expect(now).toBeGreaterThanOrEqual(last);
-    last = now;
-  }
+    var last = 0;
+    for (var i = 0; i < 100; ++i) {
+        var now = Date.now();
+        expect(now).not.toBeNaN();
+        expect(now).toBeGreaterThan(1580000000000);
+        expect(now).toBeGreaterThanOrEqual(last);
+        last = now;
+    }
 });