Add digamma function for Tensorflow frontend

[jarib047]

Close #20206

[github-actions]

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[sherry30]

Hi,

Can you try to resolve the failure in the CI
AssertionError: returned dtype = float64, ground-truth returned dtype = float32

Thanks

[jarib047]

Hello,
This error "AssertionError: returned dtype = float64, ground-truth returned dtype = float32" seems to occur due to the digamma function returning a NaN value with a different data type.

I haven't found any way to navigate around it, could you help me with this?

Thanks.