Change export_to_video default

[DN6]

What does this PR do?

There's a strange issue with the cv2 VideoWriter where setting the FPS to 8 results in a green/distorted video in Colab. Changing the default value to 10 for now so that anyone running our docs examples in Colab doesn't run into strange exports

In any case, the FPS for export_to_gif is set to 10 as well, so this would exports consistent.

Fixes # (issue)

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[HuggingFaceDocBuilderDev]

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[sayakpaul]

With an FPS of 8, do you see problems locally? If not, then I think we shouldn't change the value and instead make it clear from the documentation.

[DN6]

I was able to reproduce the issue locally too.

[sayakpaul]

Holy hell 🥹

[sayakpaul]

@DN6 let's merge this.