Fix: Remove deprecated 'initialValue' from sanitizeInputRestProps

[afilp]

Problem

I think (not 100% sure) that 'initialValue' is deprecated so it should also be removed from here?

Solution

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How To Test

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[fzaninotto]

That's right, initialValue isn't supported since v4: https://github.com/marmelab/react-admin/blob/4.x/docs/Upgrade.md#initalvalue-and-defaultvalue-have-been-merged-into-defaultvalue

Would you mind looking for other remaining instances of the same prop in sanitizers to clean them up, too?

[afilp]

I will be glad to help the great react-admin team!

I will need some time though to check, as I am in a pressure to create some features. Thanks.

[fzaninotto]

Thanks