What to do with the olive oil from canned sardines?
First, if you are going to use it, do so within a few days, and if you are not using right away, put in another container and store it in the refrigerator. As for uses, you can employ it anywhere you would use oil, and where the flavor works.  Certainly a vinaigrette or dressing.  I've seen suggestions for using it when roasting potatoes, and even on focaccia.  So, no need to dispose of it.  It is not going to be the best quality olive oil, and in some cases it is other types of oil.  However, if you enjoy the flavor and have a near term use in mind it can be used.