Option 1.
Update to registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WcmSvc\wifinetworkmanager\config
Or via Login Script or during the task sequences in Configuration Manager or MDT (post image install)
reg add HKLM\SOFTWARE\Microsoft\WcmSvc\wifinetworkmanager\config /t REG_DWORD /v AutoConnectAllowedOEM /d 0
Option 2.
Modify Unattend.xml to add Microsoft-Windows-WiFiNetworkManager
Set WiFiSenseAllowed to 0
Option 3.
For Windows 10 build 1511 or later
Configure the Group Policy Object Allow Windows to automatically connect to suggested open hotspots, to networks shared by contacts, and to hotspots offering paid services under
Computer Configuration\Administrative Templates\Network\WLAN Service\WLAN Settings\.