Is it permissible for me to transport flowers accompanied by chocolates in my work as a delivery driver in Canada, given that I do not know whether haram gelatin extracted from pigs or unslaughtered animals was used in the manufacturing of these chocolates?

There is no objection to conveying requests without researching their source or components, lest that lead to undue hardship, difficulty, and blameworthy extremism (tanattu'). Concerning this, the Messenger of Allah, peace and blessings be upon him, said: "Ruined are those who go to extremes." This refers to over-analysis, exaggeration, and imposing strictness upon oneself without necessity. Everything you encounter in the hands of an unknown person is permissible for you to eat, out of good presumption towards them.