Add an explicit dependency of urllib3~=2.0 and update processing_utils.save_url_to_cache to use urllib3 for Lite support

[whitphx]

Description

Closes: #6837

• Update processing_utils.save_url_to_cache() to use urllib3 to work on Lite as well.
• To use urllib3, add it in requirements.txt explicitly.
  • Found that the version spec (e.g. >=2.2.0) was not necessary because Pyodide ships urllib==2.1.0 which works on Pyodide and urllib>=2.2.0 supports Pyodide on its end.
  • Moreover, version spec can cause version conflicts like this, so omitting it may be better anyway.

With this PR, apps like below can work that uses examples with URLs.

import gradio as gr


demo = gr.Interface(
	fn=lambda x: x,
	inputs="image",
	outputs="image",
	examples=[
		["https://huggingface.co/datasets/Xenova/transformers.js-docs/resolve/main/cats.jpg"],
	]
)


if __name__ == "__main__":
    demo.queue().launch()

[gradio-pr-bot]

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---

Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/3b1dfba9c550749e913dff57799d31a57556fb32/gradio-4.26.0-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@3b1dfba9c550749e913dff57799d31a57556fb32#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
gradio	minor

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

With the following changelog entry.

Add an explicit dependency of urllib3~=2.0 and update processing_utils.save_url_to_cache to use urllib3 for Lite support

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

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[abidlabs]

Tested, everything works great! Should be good to merge @whitphx pending the suggestion above

[abidlabs]

Going to upgrade this to a minor since we are updating our requirements. We have a test that is failing b/c botocore does not support urllib 2 but I'm going to see if we can upgrade the version of botocore to fix this

[freddyaboulton]

What about async_save_url_to_cache? But this change looks good @whitphx

[abidlabs]

Oh good catch @freddyaboulton! @whitphx, as @freddyaboulton pointed out, async_save_url_to_cache is used in async_move_files_to_cache, and I think we'll need to patch async_save_url_to_cache to use urllib if running in wasm mode, or otherwise urls that are produced as the result of functions will not be processed correctly

[whitphx]

Thank you @abidlabs @freddyaboulton ! I missed it.
Will add the same an equivalent patch to it.

[whitphx]

Made a PR: #8026