Delete documentation inconsistency 'finally' for AR callbacks [ci skip]

[soartec-lab]

The preamble 'finally' is described in item 8.2 of the AR callback.
However, since it is not the last item, the expression 'finally' is contradictory.

When item 8.3 was added, I guessed that item 8.2 was supposed to be "finally" deleted, so I deleted it.

[kamipo]

Looks like we have one another "Finally" in the guides.

rails/guides/source/active_record_validations.md

Line 937 in 03c2bb6

Finally, it's possible to associate `:if` and `:unless` with a `Proc` object

[soartec-lab]

Is this also inconsistent with 'active_record validations.md'?
Or should we interpret the preamble 'finally' as 'fainally' in the description of ': if,: unless'?

[soartec-lab]

I also deleted 'finally' in 'active_record_validations.md' @kamipo taught.

[soartec-lab]

@kamipo

Thank you for review.
We have committed the proposal.

[kamipo]

I digged the history, but the items are not the last item from the first merge from docrails.
Anyway, the "Finally" doesn't make sense.

[soartec-lab]

merge Thank you.
I gained good insight through this contribution.