Alongside my book proposal, I included by mistake a chapter with some typos (just a few, but major).
I have never been in either pair of the shoes, but I will try to break this down: To me, it's better to lose a book deal because I reported an error in my proposal than to lose a book deal because a reviewer commented "glaring grammatical errors in the introduction."

I would suggest sending the corrected version to the editor with an apology, explaining what the errors are and invite the editor to decide if it needs to be delivered again to the reviewers. That way, you did your job as a responsible intellect, and the editor remains in control. And even the editor decides not to resend another version and later a reviewer found the errors, you're already covered from the editor's point of view. That's why I really see no harm reporting that.

Best of luck to your publishing endeavor.