Depends on the unit. Most units give a small leeway, such that if you miss or are really late to one, it won’t affect you passing or failing on attendance. I’d check the unit guide on the attendance rate and explain the situation to the unit coordinator, trying to see if attending another one (assuming no assessment occurred in this workshop) will make up for it instead. In the meantime, check when other sessions are and see if you can slot yourself in, explaining to the teacher what happened and if it’d be okay to join for the week. Usually, as long as no assessment was supposed to occur in the workshop and it isn’t full, most are generally fairly happy to accommodate one more (especially since class changes usually still happen this early in semester), as long as this situation remains a rare occurrence.
EDIT: I moved your post from the General Uni Discussion board to the Monash board as I thought it might be more appropriate there and so you could get more situation-specific advice.