fix(self-hosted): GraphiQL invalided authentication credentials (supabase#29972)

Author: alaister

apps/studio/pages/project/[ref]/api/graphiql.tsx

@@ -71,7 +71,9 @@ const GraphiQLPage: NextPageWithLayout = () => {
  ...opts,
  headers: {
  ...opts?.headers,
- Authorization: `Bearer ${accessToken}`,
+ ...(accessToken && {
+ Authorization: `Bearer ${accessToken}`,
+ }),
  'x-graphql-authorization':
  opts?.headers?.['Authorization'] ??
  opts?.headers?.['authorization'] ??