[MM-37585] (#28634)

* add tests

* pass userID to the function instead of the user object.

* remove concurrent login simulation

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/app/oauth.go

@@ -956,7 +956,7 @@ func (a *App) SwitchEmailToOAuth(c request.CTX, w http.ResponseWriter, r *http.R
 		return "", err
 	}
 
-	if err = a.CheckPasswordAndAllCriteria(c, user, password, code); err != nil {
+	if err = a.CheckPasswordAndAllCriteria(c, user.Id, password, code); err != nil {
 		return "", err
 	}