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/functions/function-missing-arg.js

@@ -1,10 +1,10 @@
 test("basic functionality", () => {
-  function foo(a, b) {
-    return a + b;
-  }
+    function foo(a, b) {
+        return a + b;
+    }
 
-  expect(foo()).toBeNaN();
-  expect(foo(1)).toBeNaN();
-  expect(foo(2, 3)).toBe(5);
-  expect(foo(2, 3, 4)).toBe(5);
+    expect(foo()).toBeNaN();
+    expect(foo(1)).toBeNaN();
+    expect(foo(2, 3)).toBe(5);
+    expect(foo(2, 3, 4)).toBe(5);
 });