fix(input): clear button can be navigated using screen reader (#29366)

Issue number: resolves #29358

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

When the clear button is focused, `focusin` is dispatched and bubbles up
to the `ion-input`. Our [scroll assist utility listens for
`focusin`](https://github.com/ionic-team/ionic-framework/blob/2fc81ddc9b35d6909fd4b585079aedabbd659233/core/src/utils/input-shims/hacks/scroll-assist.ts#L135)
to adjust the scroll position. It also causes the input to be
re-focused. As a result, when swiping to the clear button with a screen
reader, focus will be forcibly moved back to the input. This means that
users cannot swipe away from the input to the right when using a screen
reader.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- To fix this, I decided to have the `focusin` event from the clear
button not bubble (as opposed to add a really specific workaround to the
scroll assist utility).

Adding `stopPropagation` was easy enough, but it turned out that the
scroll assist listeners were all configured to listen during the capture
phase instead of the bubble phase. As a result, `stopPropgation` had no
effect because the scroll assist callback had already fired. To address
this, I updated the listeners to listen during the bubbling phase
instead of the capture phase. Based on my testing the capture phase was
not required for scroll assist to work, so it appears safe to remove.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!--
  If this introduces a breaking change:
1. Describe the impact and migration path for existing applications
below.
  2. Update the BREAKING.md file with the breaking change.
3. Add "BREAKING CHANGE: [...]" to the commit description when merging.
See
https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#footer
for more information.
-->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

Dev build: `8.0.1-dev.11713535425.1a4afba3`

Reviewers: Please test this on a physical iOS device and be sure to test
the scroll assist behavior. There is a test at
http://localhost:3333/src/utils/input-shims/hacks/test you can use.

core/src/components/input/input.tsx

@@ -783,6 +783,15 @@ export class Input implements ComponentInterface {
                    */
                   ev.preventDefault();
                 }}
+                onFocusin={(ev) => {
+                  /**
+                   * Prevent the focusin event from bubbling otherwise it will cause the focusin
+                   * event listener in scroll assist to fire. When this fires, focus will be moved
+                   * back to the input even if the clear button was never tapped. This poses issues
+                   * for screen readers as it means users would be unable to swipe past the clear button.
+                   */
+                  ev.stopPropagation();
+                }}
                 onClick={this.clearTextInput}
               >
                 <ion-icon aria-hidden="true" icon={mode === 'ios' ? closeCircle : closeSharp}></ion-icon>

core/src/utils/input-shims/hacks/scroll-assist.ts

@@ -124,7 +124,7 @@ export const enableScrollAssist = (
   const focusOut = () => {
     hasKeyboardBeenPresentedForTextField = false;
     win?.removeEventListener('ionKeyboardDidShow', keyboardShow);
-    componentEl.removeEventListener('focusout', focusOut, true);
+    componentEl.removeEventListener('focusout', focusOut);
   };
 
   /**
@@ -155,15 +155,15 @@ export const enableScrollAssist = (
     );
 
     win?.addEventListener('ionKeyboardDidShow', keyboardShow);
-    componentEl.addEventListener('focusout', focusOut, true);
+    componentEl.addEventListener('focusout', focusOut);
   };
 
-  componentEl.addEventListener('focusin', focusIn, true);
+  componentEl.addEventListener('focusin', focusIn);
 
   return () => {
-    componentEl.removeEventListener('focusin', focusIn, true);
+    componentEl.removeEventListener('focusin', focusIn);
     win?.removeEventListener('ionKeyboardDidShow', keyboardShow);
-    componentEl.removeEventListener('focusout', focusOut, true);
+    componentEl.removeEventListener('focusout', focusOut);
   };
 };