I don't know of any country having a numerical limit on how many citizenships their citizens may have: either they allow multiple citizenships or they don't.
France allows it by not disallowing it in law, but it is also explicitly stated in various governmental sources that multiple citizenships are allowed. For example, on the Foreign Ministry's website:
La possession d’une ou de plusieurs autres nationalités, n’a pas, en
principe, d’incidence sur la nationalité française.
Par ailleurs, la France ne fait aucune distinction entre les
binationaux et les autres Français sur le plan des droits et devoirs
liés à la citoyenneté.
Which translates into "Holding one or more other citizenships has no incidence on French citizenship. France does not make any distinction between dual citizens and other French citizens regarding rights and duties linked to citizenship"
And even though it does not address the issue directly, according to Canadian government:
In some situations, you might decide that you want to renounce (give
up) your Canadian citizenship. For example, if you are or want to
become a citizen of a country that does not allow dual citizenship,
you may choose to renounce your Canadian citizenship.
which seems to imply that Canada does allow it.