remove redundant event source logic

[hannahblair]

Description

The old event source logic was mistakenly added back in in #8181. This removes that.

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[gradio-pr-bot]

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Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/53e277814c0551d093d9ed55c8630c3e04ca7633/gradio-4.28.3-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@53e277814c0551d093d9ed55c8630c3e04ca7633#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
@gradio/client	minor
gradio	minor

• Maintainers can select this checkbox to manually select packages to update.

With the following changelog entry.

remove redundant event source logic

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[pngwn]

Thanks for cleaning up @hannahblair!