Allow deprecated regridding scheme linear_extrapolate in recipe checks

[schlunma]

Description

In the preprocessor function regrid, the usage of the deprecated regridding scheme linear_extrapolate is allowed. However, the corresponding recipe check does not. This PR fixes that.

Closes #2323

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[valeriupredoi]

smashing! Cheers, Manu! Do you not want to plop a deprecation warning in there at return point too?