DEPR: future.no_silent_downcasting option

[jbrockmendel]

Pandas version checks

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• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

NA

Issue Description

The option no longer does anything in 3.0, so can be deprecated. The few places where we use it in the code can be removed.

Expected Behavior

NA

Installed Versions

Replace this line with the output of pd.show_versions()

[mroeschke]

There's a PR in progress here #57872