LibJS: Uncomment the tests that pass now

Author: https://github.com/Cleverking2003
Commit: 1dbd264239
Pull-request: https://github.com/SerenityOS/serenity/pull/4622
Issue: https://github.com/SerenityOS/serenity/issues/4543

Libraries/LibJS/Tests/builtins/Math/Math.acosh.js

@@ -5,5 +5,5 @@ test("basic functionality", () => {
     expect(Math.acosh(0)).toBeNaN();
     expect(Math.acosh(0.5)).toBeNaN();
     expect(Math.acosh(1)).toBeCloseTo(0);
-    // FIXME: expect(Math.acosh(2)).toBeCloseTo(1.316957);
+    expect(Math.acosh(2)).toBeCloseTo(1.316957);
 });