fix(segment-button): correct color for button childs (#30891)

Issue number: internal


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## What is the new behavior?
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this PR. -->
- guarantee that every child of segment-button has color: primary-color
when checked;

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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Sample:
https://ionic-framework-git-rou-12439-ionic1.vercel.app/src/components/segment/test/basic?ionic:theme=ionic

core/src/components/segment-button/segment-button.ionic.scss

@@ -64,18 +64,18 @@
 }
 
 // Segment Button: Checked
+// All slot content should have the checked color even when it's not label or icon
 // --------------------------------------------------
 
-:host(.segment-button-checked) ::slotted(ion-label),
-:host(.segment-button-checked) ::slotted(ion-icon) {
+:host(.segment-button-checked) ::slotted(*) {
   color: var(--color-checked);
 }
 
 // Segment Button: Disabled
+// All slot content should have the disabled color even when it's not label or icon
 // --------------------------------------------------
 
-:host(.segment-button-disabled) ::slotted(ion-label),
-:host(.segment-button-disabled) ::slotted(ion-icon) {
+:host(.segment-button-disabled) ::slotted(*) {
   color: var(--color-disabled);
 }