Set registry key HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WinRM\Service AllowAutoConfig to 0.
Or if remote management is not needed, stop and disable service "Windows Remote Management (WS-Management)"

https://4sysops.com/wiki/disable-powershell-remoting-disable-psremoting-winrm-listener-firewall-and-localaccounttokenfilterpolicy/

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/disable-psremoting?view=powershell-7

https://docs.microsoft.com/en-us/windows-server/administration/server-manager/configure-remote-management-in-server-manager#to-enable-server-manager-remote-management-by-using-the-command-line