fix(angular): set active segment button when dynamically changing items (#29418)

Issue number: resolves #29414

---------

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## What is the current behavior?
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In Angular when the segment buttons are dynamically rendered, the
segment will not set the active visual state for the selected segment
after the re-render.

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

- In Angular the segment will set the active item visually when the
items are dynamically changed

Previously this PR:
https://github.com/ionic-team/ionic-framework/pull/28837 aimed to
resolve https://github.com/ionic-team/ionic-framework/issues/28816. I
have confirmed that the modified approach in the dev-build fixes #29414
and #28816 and the previous change is no longer needed.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

Dev-build: `8.0.2-dev.11714411675.10f48160`

core/src/components/segment/segment.tsx

@@ -141,14 +141,6 @@ export class Segment implements ComponentInterface {
   async componentDidLoad() {
     this.setCheckedClasses();
 
-    /**
-     * If the value changes before watchers
-     * are setup, then the ionSelect watch callback
-     * will not fire. As a result, we manually
-     * fire this event when Select is loaded.
-     */
-    this.ionSelect.emit({ value: this.value });
-
     /**
      * We need to wait for the buttons to all be rendered
      * before we can scroll.
@@ -495,6 +487,15 @@ export class Segment implements ComponentInterface {
     }
   };
 
+  private onSlottedItemsChange = () => {
+    /**
+     * When the slotted segment buttons change we need to
+     * ensure that the new segment buttons are checked if
+     * the value matches the segment button value.
+     */
+    this.valueChanged(this.value);
+  };
+
   private getSegmentButton = (selector: 'first' | 'last' | 'next' | 'previous'): HTMLIonSegmentButtonElement | null => {
     const buttons = this.getButtons().filter((button) => !button.disabled);
     const currIndex = buttons.findIndex((button) => button === document.activeElement);
@@ -573,7 +574,7 @@ export class Segment implements ComponentInterface {
           'segment-scrollable': this.scrollable,
         })}
       >
-        <slot></slot>
+        <slot onSlotchange={this.onSlottedItemsChange}></slot>
       </Host>
     );
   }