Delete the downloaded update package
Please make sure you already deleted the downloaded update package in
Settings > General > iPhone Storage.
If you don't see any downloaded update package of iOS or iPadOS appear here, move on to the next step.
Install Profile
Download the profile here.
Your device will prompt you to allow the profile to download.
Once allowed, open Settings, tap the profile and follow the onscreen instructions to allow installation.
Remember to restart
Don't forget to restart your device after installing the profile so any changes can be applied.
After restart, the Software Updates section in the Settings app should read that you are up to date regardless of the iOS version you have installed.
To reverse changes, simply remove the profile from settings and restart your device.