I don’t have a Windows 11 machine available, so I can’t get you the exact command, but this should get you there.
It should remove it from all users on the laptop, and (hopefully!) prevent it from coming back:
Open Powershell and run:
Get-AppxProvisionedPackage -Online | Where-Object {$_.displayname -like "*Copilot*"}
Copy the Package Name entry and run the following command, with PACKAGENAME replaced by what you just copied:
Remove-AppxProvisionedPackage -online -packagename PACKAGENAME