docs(providers): remove refresh-backed profile bullet

Signed-off-by: John Myers <9696606+johntmyers@users.noreply.github.com>

Author: johntmyers

docs/sandboxes/providers-v2.mdx

@@ -59,7 +59,6 @@ Providers v2 currently includes these user-facing features:
 - Runtime sandbox provider lifecycle commands under `openshell sandbox provider list|attach|detach`.
 - Credential refresh configuration with `openshell provider refresh status|configure|rotate|delete`.
 - Credential expiry metadata with `openshell provider update --credential-expires-at`; values accept Unix epoch milliseconds or ISO/RFC3339 timestamps.
-- Built-in refresh-backed provider profiles for `outlook` and `google-drive`.
 
 ## Roadmap