fix(input, textarea): input does not block floating label (#27870)

Issue number: resolves #27812

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issue. -->

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

We currently have CSS to ensure the floating/stacked label is not
obscured by the input/textarea when using the outline styles. However,
it was discovered that this scenario can happen with any
floating/stacked label not just when the input/textarea is using the
outline style.

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

- Floating/stacked labels appear on top of the input/textarea regardless
of fill mode.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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and migration path for existing applications below. -->


## Other information

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


Dev build: `7.2.1-dev.11690464203.1b2b4419`

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Co-authored-by: ionitron <hi@ionicframework.com>

core/src/components/textarea/textarea.scss

@@ -629,6 +629,13 @@
   @include padding(0px);
 
   max-width: 100%;
+
+  /**
+   * The 2 ensures the label
+   * remains on top of any browser
+   * autofill background too.
+   */
+  z-index: 2;
 }
 
 /**