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/operators/delete-global-variable.js

@@ -1,9 +1,9 @@
 a = 1;
 
 test("basic functionality", () => {
-  expect(delete a).toBeTrue();
+    expect(delete a).toBeTrue();
 
-  expect(() => {
-    a;
-  }).toThrowWithMessage(ReferenceError, "'a' is not defined");
+    expect(() => {
+        a;
+    }).toThrowWithMessage(ReferenceError, "'a' is not defined");
 });