Can I play Cyberpunk Steam Edition on two devices with the same savegame?

This is more a question about Steam than Cyberpunk 2077. Steam allows you to synchronize saves across multiple devices. The Steam product page indicates that Cyberpunk 2077 supports Steam Cloud, so yes - as long as you're logged in on the same account on both devices, it should synchronize your save and allow you to continue where you left off.

This is certainly the case with other games that support Steam Cloud and is certainly the case when installing Cyberpunk 2077 via GOG so I anticipate no issues with using your synchronized save across multiple devices.