feat: drop get_device_warnings; the pending updates are the fact (0.3.0)

updates_available came from the cached firmware status with ten package
names; netOrk builds it from get_available_updates with the full list
(netOrk #1111).

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-opnsense"
-version = "0.2.0"
+version = "0.3.0"
 description = "NAPALM driver for OPNsense (read-only via REST API)."
 readme = "README.md"
 license = { text = "Apache-2.0" }