You can do this via the Graph API or EWS, however you need to process the items individually. There is no automated solution, if that's what you are looking for. I suppose you can do something with Power automate flow, though again no ready-to-use template exists.
Out of curiosity, why do you care about such items? They should not be interfering with the regular booking process, and given the large quota of a room mailbox in Exchange Online, I doubt they will cause issues on that front either.