ref(relay): Only update internal state when it changed (#76594)

Removes the `is_internal` update from the `relay_from_id` function, to
move the check to the endpoint (where it already was anyways). All
additional uses of `relay_from_id` don't seem to care about the internal
state, except authentication.
So that seems fine, also this behaviour does seem more consistent.

src/sentry/api/authentication.py

@@ -132,7 +132,6 @@ def relay_from_id(request: Request, relay_id: str) -> tuple[Relay | None, bool]:
  else:
  try:
  relay = Relay.objects.get(relay_id=relay_id)
- relay.is_internal = is_internal_relay(request, relay.public_key)
  return relay, False # a Relay from the database
  except Relay.DoesNotExist:
  return None, False # no Relay found
@@ -223,6 +222,9 @@ def authenticate_credentials(
  if relay is None:
  raise AuthenticationFailed("Unknown relay")
 
+ if not static:
+ relay.is_internal = is_internal_relay(request, relay.public_key)
+
  try:
  data = relay.public_key_object.unpack(request.body, relay_sig, max_age=60 * 5)
  request.relay = relay

src/sentry/api/endpoints/relay/register_response.py

@@ -90,7 +90,7 @@ def post(self, request: Request) -> Response:
  relay = Relay.objects.create(
  relay_id=relay_id, public_key=public_key, is_internal=is_internal
  )
- else:
+ elif relay.is_internal != is_internal:
  # update the internal flag in case it is changed
  relay.is_internal = is_internal
  relay.save()