fix(lint): resolve pyright and pylint issues in provider/backend changes

- Remove unused Bottle import from docker/backend.py (pyright)
- Suppress wrong-import-position on circular-import-avoiding
  deferred imports in backend/__init__.py (pylint C0413)
- Add encoding="utf-8" to read_text() in smolmachines provision
  test (pylint W1514)
- Suppress consider-using-with on TemporaryDirectory setUp pattern
  in both provision test files (pylint R1732)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot_bottle/backend/__init__.py

@@ -411,8 +411,8 @@ class BottleBackend(ABC, Generic[PlanT, CleanupT]):
 # Import concrete backend classes AFTER the base types are defined, so
 # each backend module can pull BottleSpec / BottlePlan / BottleBackend
 # via `from . import ...` without hitting a partially-initialized module.
-from .docker import DockerBottleBackend  # noqa: E402
-from .smolmachines import SmolmachinesBottleBackend  # noqa: E402
+from .docker import DockerBottleBackend  # noqa: E402  # pylint: disable=wrong-import-position
+from .smolmachines import SmolmachinesBottleBackend  # noqa: E402  # pylint: disable=wrong-import-position
 
 
 # The dict is heterogeneous: each value is a BottleBackend specialized

bot_bottle/backend/docker/backend.py

@@ -25,7 +25,7 @@ from pathlib import Path
 from typing import Generator, Sequence
 
 from ...supervise import SUPERVISE_HOSTNAME, SUPERVISE_PORT
-from .. import ActiveAgent, Bottle, BottleBackend, BottleSpec
+from .. import ActiveAgent, BottleBackend, BottleSpec
 from . import cleanup as _cleanup
 from . import enumerate as _enumerate
 from . import launch as _launch