"repertum et" would presumably be a misreading for "repertum est". The Latin of the final phrase would therefore be as follows:

...nec quidquam impedimenti repertum est —neque canonis neque regis — quominus in facie Ecclesiae copulari potuerint.

("...nor was any impediment found — either canonical or royal — that would make them unable to be married before the Church.")

As indicated in the discussion, "negi" here must almost certainly be a misreading of "neque". It cannot in any way be connected with the verb "negō" (I deny) because 1) it would have to be either an infinitive (negare, negari) or a subjunctive (neget, negetur), and none of these contains "negi", 2) if the "et" is a misreading of "est", then the main sentence has a complete predicate (est) and the subordinate clause (quominus ... copulari potuerint) also has a complete predicate (potuerint), leaving no grammatical role (or subject) for any act of "denial", and 3) since the canons in question are simply written documents rather than living actors, the use of the verb "negō" with them would be strange, and a verb such as "vetō", "prohibeō", or "repugnō" would almost certainly need to be used instead.

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Note added at 5 days (2022-06-02 13:44:56 GMT)
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Thank you for sending me the photo. I would transcribe the entry as follows (uncertain letters replaced by asterisks):

Secùndùm Statùta Sacri Consilij Tridentini rite matrimo-
nio copulatùs est die quinta mensis februarij 1697 honestùs
Joannes Mayer filiùs legittimus Joannis Mayer, Et Ursulæ
Moch Ex domi**tù Suncio. in Hybernia cùm honesta
Susanna. filia legittima Jacobi daul Et Margaretæ præfa
ti uxori* ex g***enheim nec quidquam impedimenti
repertùm est neque canonici, neque regij quominus in facie Eccliæ
copùlari potuerint

So, the actual wording is in fact "est neque canonici, neque regij quominus", and the fact that "neque canonici, neque regij" means "neither canonical nor royal" is made even clearer from alternate wording that the same pastor uses in other marriage entries on those same pages:

— nullum neque Canonicum, neque Regium impedimentum repertum est
— nihil repertum est, neque Canonicum neque Regium impedimentum
— nec impedimentum, neque Regium, neque Canonicum repertum
— nullum impedimentum neque canonicum, neque regium repertum est
— nec ullum impedimentum Canonicum vel Regium repertum est
— nec quidquam impedimenti repertum est neque canonici, neque regij
— nullum impedimentum neque canonicum neque regium repertum fuerit
— nec impedimentum Regium sive Canonicum repertum est
— nec impedimentum Canonicum vel Regium repertum esse

What was transcribed as "prata ti" was in fact "præfa" at the end of one line and "ti" at the beginning of the next line. (There may be a hyphen after "præfa" to show that the two word fragments are connected, but the image is so dark there that I can't be sure.) Together this makes "præfati", i.e., "of the aforesaid", so that the pastor is saying that Susanna is the legitimate daughter of Jacob Daul and of Margareta, the wife of the aforesaid (i.e., the wife of Jacob).