So we would expect Arduino IDE to have installed this Arduino_CloudUtils library dependency, but clearly that didn't happen. There are a couple of possible explanations for the missing dependency:
You declined the offer to install dependencies.
You updated the library by clicking the "INSTALL ALL" button in the updatable libraries notification (this feature has a bug that causes it to skip the installation of dependencies)
The solution to the problem will be to install the missing dependency. I'll provide instructions you can follow to do that:
Select Sketch > Include Library > Manage Libraries... from the Arduino IDE menus to open the "Library Manager" view in the left side panel.
Type Arduino_CloudUtils in the "Filter your search..." field.
Find the "Arduino_CloudUtils" entry in the list of search results.
You will see an "INSTALL" button at the bottom of the entry. Click the button.
Wait for the installation process to finish, as indicated by a notification at the bottom right corner of the Arduino IDE window:
ⓘ Successfully installed library ...
After doing that, you can use Library Manager to update the "ArduinoIoTCloud" library back to the latest version. The "Arduino_TinyCBOR.h: No such file or directory" error should no longer occur.