Remove deprecated .update() usage from Interface internals

[abidlabs]

We used the .update() logic various places inside Interface, which meant that a warning was raised e.g. any time you clicked on the Clear button or passed in an iterator. This replaces with modern syntax.

Test code:

import gradio as gr
import time

def identity(x):
    for i in range(len(x)):
        time.sleep(0.5)
        yield x[:i+1]
        
gr.Interface(identity, "textbox", "textbox").queue().launch()

[gradio-pr-bot]

🪼 branch checks and previews

•	Name	Status	URL
	Spaces	ready!	Spaces preview
	Website	ready!	Website preview
	Storybook	ready!	Storybook preview
	Visual tests	all good!	Build review
🦄	Changes	detected!	Details

---

Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/f6120b83ca73c9173c96013e5c22dd99e7d7da74/gradio-3.47.1-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@f6120b83ca73c9173c96013e5c22dd99e7d7da74#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
gradio	patch

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

With the following changelog entry.

Remove deprecated .update() usage from Interface internals

Maintainers or the PR author can modify the PR title to modify this entry.

Something isn't right?

• Maintainers can change the version label to modify the version bump.
• If the bot has failed to detect any changes, or if this pull request needs to update multiple packages to different versions or requires a more comprehensive changelog entry, maintainers can update the changelog file directly.

[freddyaboulton]

There's a usage of update in the theme builder but other than that this looks good to me @abidlabs

gradio/gradio/themes/builder_app.py

Line 969 in 4e0d87e

gr.Markdown.update(

[abidlabs]

Thanks for the review @freddyaboulton and nice catch. I'll fix the theme builder too and get this in.