Fix Dropdown change event when allow_custom_value is true

[freddyaboulton]

Description

Closes: #12548

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Install Gradio from this PR

pip install https://gradio-pypi-previews.s3.amazonaws.com/905dd4e2b3a27904a11adea39ba3c261dc7b4fcd/gradio-6.1.0-py3-none-any.whl

Install Gradio Python Client from this PR

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[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
@gradio/dropdown	patch
gradio	patch

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• Fix Dropdown change event when allow_custom_value is true

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