core: Google Assistant device sync broken in 0.93.0b4

Home Assistant release with the issue:

0.93.0b4

Last working Home Assistant release (if known): 0.92.2

Operating environment (Hass.io/Docker/Windows/etc.):

Docker. homeassistant/raspberrypi3-homeassistant

Component/platform:

https://www.home-assistant.io/components/google_assistant/

Description of problem: Syncing devices no longer works. Downgrading to 0.92.2 allows syncing devices to work again.

Problem-relevant configuration.yaml entries and (fill out even if it seems unimportant):

google_assistant:
  project_id: REDACTED
  api_key: REDACTED
  exposed_domains:
    - switch
    - light
    - scene
    - media_player
    - cover

Additional information: Debug logging of the google_assistant component yields nothing interesting.