Remove unstable MSC2858 API, including `experimental.msc2858_enabled` config option (#10693)

Signed-off-by: Sean Quah <seanq@element.io>

1 files changed, 0 insertions, 5 deletions

diff --git a/synapse/handlers/sso.py b/synapse/handlers/sso.py

index 0e6ebb574e..0fdc6dd9e7 100644
--- a/synapse/handlers/sso.py
+++ b/synapse/handlers/sso.py
@@ -104,11 +104,6 @@ class SsoIdentityProvider(Protocol):
         """Optional branding identifier"""
         return None
 
-    @property
-    def unstable_idp_brand(self) -> Optional[str]:
-        """Optional brand identifier for the unstable API (see MSC2858)."""
-        return None
-
     @abc.abstractmethod
     async def handle_redirect_request(
         self,