First of all and above all - don't panic!
To begin with, IRCC will process, review and make a decision on your application regardless of wether you send them information about your deferral or not. The only difference might be that they will issue your study permit from September 2022 instead of Winter 2023, which in the end of the day doesn't make any difference since it will be a positive result and you can extend your visa once you are already in Canada. And also, the IRCC might issue you SP for Winter 2023 because they do realize that they are delaying the processing and people do defer their programs. Also notice a very important thing - the IRCC has recently made an official statement asking the students, who have not received their visas yet, to talk to their respective colleges and universities and ask for the deferral - BUT - the IRCC has not asked students to inform the IRCC about their deferrals. I think this is crucial to notice, they do not ask us to inform them because they understand everything. So this is to my point about keeping it cool and not worrying about informing the IRCC at all.
However, having said that, it is a good idea to send your documents to the IRCC and inform them about your deferral. To do this, you need to get your confirmation of enrollment and official letters from the university with regards to (1) your deferral and (2) your scholarship. The (1) is pretty easy. The (2) might be complicated depending on the financial documents you have submitted with your application to prove that you are able to support your education and stay in Canada. In case you rely only on your scholarship and now you will only have 50% of it, you will have to explain to the IRCC how you are going to support the other 50% of your tuition fees. If that is not a problem for you, just attach the new financial documents. If it is a problem, maybe do not contact IRCC at this point at all and let them make a decision based on the first documents that you have provided. In this case, you will have to still submit more documents about your finances, but later when you will extend your visa in Canada (in case they issue your SP for September). It really is complicated when it comes to financial proof, so think about it carefully. And ask for advise from your university. I would not suggest to hide anything from the IRCC, you have to be absolutely honest with them. So, to do this, you have to get your financial documents in order before contacting them.