chore(project): Remove useless custom elementAtOrNull function

Author: Pyozer

Diff for: lib/src/helper.dart

@@ -2,13 +2,6 @@ extension CustomList<T> on List<T> {
   List<T> asReversed(bool isReverse) {
     return isReverse ? reversed.toList() : this;
   }
-
-  T? elementAtOrNull(int index) {
-    try {
-      return this[index];
-    } catch (_) {}
-    return null;
-  }
 }
 
 bool isBackgroundImageAssetPathValid(String assetPath) {

Diff for: lib/src/introduction_screen.dart

@@ -548,7 +548,9 @@ class IntroductionScreenState extends State<IntroductionScreen> {
     Widget? leftBtn;
     // show skip button when skip is enabled and back is disabled,
     // or show it on the first page when back is enabled.
-    if (widget.showSkipButton && ((getCurrentPage() == 0 && widget.showBackButton) || !widget.showBackButton)) {
+    if (widget.showSkipButton &&
+        ((getCurrentPage() == 0 && widget.showBackButton) ||
+            !widget.showBackButton)) {
       leftBtn = Visibility(
         visible: !isLastPage && !_isSkipPressed,
         maintainState: true,
@@ -604,9 +606,8 @@ class IntroductionScreenState extends State<IntroductionScreen> {
     final pages = widget.pages
             ?.mapIndexed((index, page) => IntroPage(
                   page: page,
-                  scrollController: CustomList(
-                    widget.scrollControllers,
-                  )?.elementAtOrNull(index),
+                  scrollController:
+                      widget.scrollControllers?.elementAtOrNull(index),
                 ))
             .toList() ??
         widget.rawPages!;

Diff for: test/src/helper_test.dart

@@ -13,17 +13,5 @@ void main() {
     test('asReversed() returns original list when isReverse is false', () {
       expect(originalList.asReversed(false), [1, 2, 3, 4, 5]);
     });
-
-    test('elementAtOrNull returns the correct element for valid index', () {
-      expect(originalList.elementAtOrNull(1), 2);
-    });
-
-    test('elementAtOrNull returns null for out of bounds index', () {
-      expect(originalList.elementAtOrNull(5), isNull);
-    });
-
-    test('elementAtOrNull returns null for negative index', () {
-      expect(originalList.elementAtOrNull(-1), isNull);
-    });
   });
 }