Adjusted some import locations to prevent circular imports. Moved `craft_providers/bases/instance_config.py` to `craft_providers/instance_config.py` Added `timeout` argument (in seconds) into executors. All external calls now have a pre-defined timeout. Default timeout constants: * Simple task 1 min * Complex task 10 mins * Unpredictable task 60 mins * Network check timeout 10 seconds Added `timeout` argument (in seconds) into lxc and multipass executors. Removed `_check_deadline(deadline)`. Global total timeout is no longer supported. All base class now use `self.executor`, no longer accept `(executor=executor, deadline=deadline)` All supported base images will now use a shared base. All images will be pre-installed with `build-essential` (or equivalent), `git`, and `python3` (with `devel`, `pip`, `venv`, `setuptools`, `wheel`) Packages update cache files will be cleared before finish the image. They are unlikely be used again and save space and time when create new instances. CRAFT-1717 CRAFT-1475 https://github.com/canonical/craft-providers/issues/146 https://github.com/canonical/charmcraft/issues/1047