As I recall it (and as 237SJ's post seems to confirm), MOT test centres weren't actually closed during the first lockdown. It was just accepted that there might have been problems with testing capacity due to many testers having to self-isolate, so people were given extra time to get their vehicles tested. (i.e. MOT testing was still actually available as long as there were the staff to carry out the tests).
On that basis it would seem that your MOT test on 9 November can go ahead as long as the testers aren't self-isolating. The only problem might be as to whether you're allowed to leave home to take the car for its test. Such a purpose isn't listed on the Gov.uk website but it does state "This list is not exhaustive and there are other limited circumstances where you may be permitted to leave or be outside of your home. These will be set out in law and further detailed guidance will be provided":
https://www.gov.uk/guidance/new-national-restrictions-from-5-november?priority-taxon=774cee22-d896-44c1-a611-e3109cce8eae#stay-at-home
So it might be a case of "Wait and see!"