fix(lint): remove trailing blank line from idp_service.go

goimports requires files to end with a single newline. The security
commit left an extra blank line when it removed the trailing
redactIdentityProviderResponse function.

https://claude.ai/code/session_01DVhwUL8RG8HVrcChv5qHdh

server/router/api/v1/idp_service.go

@@ -233,4 +233,3 @@ func convertIdentityProviderConfigToStore(identityProviderType v1pb.IdentityProv
 	}
 	return nil
 }
-