Fix matplotlib image size

[freddyaboulton]

Description

Fixes #3210 . Modifies the matplotlib css so that max_height is not set (this was making all the plots tiny) and removes width so that the plot size reflects the python configuration.

You can test with outbreak_forecast and this demo:

import matplotlib
import matplotlib.pyplot as plt
import gradio as gr

matplotlib.use("Agg")

def make_plot(width, height):
    fig, ax = plt.subplots(figsize=(width, height))
    fruits = ['apple', 'blueberry', 'cherry', 'orange']
    counts = [40, 100, 30, 55]
    bar_labels = ['red', 'blue', '_red', 'orange']
    bar_colors = ['tab:red', 'tab:blue', 'tab:red', 'tab:orange']

    ax.bar(fruits, counts, label=bar_labels, color=bar_colors)

    ax.set_ylabel('fruit supply')
    ax.set_title('Fruit supply by kind and color')
    ax.legend(title='Fruit color')
    fig.savefig(f"{width}_{height}.png")

    return fig

with gr.Blocks() as demo:
    with gr.Row():
        with gr.Column():
            width = gr.Slider(1, 10, step=1, value=1, label="width")
            height = gr.Slider(1, 10, step=1, value=1, label="height")
        with gr.Column():
            plot = gr.Plot()
    
    width.change(make_plot, [width, height], [plot])
    height.change(make_plot, [width, height], [plot])
    demo.load(make_plot, [width, height], [plot])

demo.launch()

Outbreak forecast before

Outbreak forecast after

test demo before

test demo after

Checklist:

• I have performed a self-review of my own code
• I have added a short summary of my change to the CHANGELOG.md
• My code follows the style guidelines of this project
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

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Please add a brief summary of the change to the Upcoming Release > Full Changelog section of the CHANGELOG.md file and include
a link to the PR (formatted in markdown) and a link to your github profile (if you like). For example, "* Added a cool new feature by [@myusername](link-to-your-github-profile) in [PR 11111](https://github.com/gradio-app/gradio/pull/11111)".

If you would like to elaborate on your change further, feel free to include a longer explanation in the other sections.
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[gradio-pr-bot]

All the demos for this PR have been deployed at https://huggingface.co/spaces/gradio-pr-deploys/pr-3274-all-demos

[abidlabs]

So much nicer, LGTM!

[pngwn]

lgtm!

[freddyaboulton]

Thanks for the reviews @pngwn @abidlabs !