refactor!: drop the _docker_bin override

napalm-linux 0.3.0 drops the Docker CLI methods the override served.
_container_engine_binary("docker") returns Container Station's path
itself, which is all netOrk needs: it reaches the engine through
open_container_engine (NetOrk/netork#765, phase 9).

Requires napalm-linux >= 0.3.0. Version 0.3.0.

napalm_qnap_qts/qnap_qts.py

@@ -150,14 +150,10 @@ class QnapQtsDriver(StorageDriver, HypervisorDriver, LinuxDriver):
             return None
         return found.splitlines()[0].strip() or None if found else None
 
-    def _docker_bin(self) -> str:
-        """Override LinuxDriver's hook: docker is not on PATH under QTS."""
-        return getattr(self, "_docker_path", None) or "docker"
-
     def _container_engine_binary(self, engine: str) -> str:
         """Container Station keeps docker off PATH; callers never see the path."""
         if engine == "docker":
-            return self._docker_bin()
+            return getattr(self, "_docker_path", None) or "docker"
         return super()._container_engine_binary(engine)
 
     # ── QPKG, not apt ─────────────────────────────────────────────────────────