In the simplified version of Python grammar at https://docs.python.org/3.10/reference/grammar.html, most 'invalid_<rule>' from the complete grammar at https://github.com/python/cpython/blob/3.10/Grammar/python.gram have been removed, but 2 of them remain :

primary:
    | invalid_primary  # must be before 'primay genexp' because of invalid_genexp

dict:
    | '{' invalid_double_starred_kvpairs '}'

I suppose that the simplified version is extracted from the complete grammar with a program, and this program doesn't detect the 'invalid_<rule>' that don't end the line, since these 2 occurrences correspond to the only such lines in the complete grammar

primary[expr_ty]:
    | invalid_primary  # must be before 'primay genexp' because of invalid_genexp

dict[expr_ty]:
    | '{' invalid_double_starred_kvpairs '}'

Also note the typo in the comment : 'primay genexp' instead of 'primary genexp'