Fix right button of TextField component shrinking bug (#2375)

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## Self Checklist

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**label** to the PR.
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## Related Issue

<!-- Please link to issue if one exists -->

<!-- Fixes #0000 -->

- resolves #2280

## Summary

<!-- Please brief explanation of the changes made -->

- `TextField`의 rightContent로 오는 컴포넌트의 width 가 고정되는 버그를 수정합니다. 

## Details

<!-- Please elaborate description of the changes -->

| As-is| To-be |
|--------|--------|
| <img width="356" alt="image"
src="https://github.com/user-attachments/assets/7b0ee373-d3bd-4c9e-91bb-afdd148691a2">
| <img width="364" alt="image"
src="https://github.com/user-attachments/assets/680339fd-5214-4128-ab00-487582763fce">
|

### Breaking change? (Yes/No)

<!-- If Yes, please describe the impact and migration path for users -->

-  No

## References

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aware of -->

- None

.changeset/little-llamas-attend.md

@@ -0,0 +1,5 @@
+---
+'@channel.io/bezier-react': patch
+---
+
+Prevent right button of `TextField` from shrinking.

packages/bezier-react/src/components/TextField/TextField.module.scss

@@ -104,6 +104,7 @@
 
 .RightContentWrapper {
   display: flex;
+  flex-shrink: 0;
   align-items: center;
   padding-right: 2px;
 }