Is a prohibition on night flying normally endorsed on a Part-FCL PPL(A) which does not include a night rating?
Endorsed by who?
An EASA Part.FCL PPL(A) does not include NVFR privileges by definition, so there is no need to explicitly endorse the obvious.
Night is usually endorsed positive in Section XII, Class/Type/IR, Remarks and Restrictions. I do not know of any NationalAA explicitly listing the non-existance of a night rating, but one can not rule out a country doing that.
There are situations you may find a night prohibition in such a license. Most of that is derived from medical and would endorse as VCL (valid by day only) in Section XIII. Further on, as E-IR and CB-IR in principle would allow for day only IR (no discussion on sense please), there could be such a restriction in the license.
So, there could, but usually it is not.