BUG: raise error when converting NaT to int

[Alvaro-Kothe]

• closes BUG: converting null timedelta to int with astype() changes NaT to -9223372036854775808 #59711 (Replace xxxx with the GitHub issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

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I had to branch out between finite and NA-only in check_to_int_nansafe because of this error:

E TypeError: ufunc 'isfinite' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

Infinite values in datetime-like types when casting to int raises other errors, for example:

• overflow: when the series contains only the inf.
• TypeError: when the series contains inf and another value.

[jbrockmendel]

It is t clear this is what we want to do. There was discussion about allowing int casting at all.

[Alvaro-Kothe]

It is t clear this is what we want to do.

Ok, let me know if this should be closed.

There was discussion about allowing int casting at all.

Do you have the issue/PR number for the record?

[jbrockmendel]

not off the top of my head. i suspect it was opened by joris

[Alvaro-Kothe]

@jbrockmendel please, confirm if it's this one: #45588

[jbrockmendel]

#45034