Use shutil for cross-volume moves

[piercefreeman]

We leverage the local "/tmp" directory extensively in building so we can avoid polluting the local project filesystem until we are sure that we have a successful build result. Upon completion, we want to move files from the temporary directory to the local project. Mostly this is okay since we operate within the same device - but there are some situations (docker, remote CI builds, booting from removable storage) where the OS's default /tmp path is on a different volume than the project itself. Our previous logic would crash in these cases with a Invalid cross-device link error.

This PR fixes this bug by moving to shutil.move for moving temporary files. It will default to a regular replace while within the same volume and fallback to a copy/delete in the case of differing volumes.

11.66   File "/root/.cache/pypoetry/virtualenvs/myproject-VA82Wl8V-py3.11/lib/python3.11/site-packages/mountaineer/cli.py", line 422, in handle_build
11.66     js_compiler.build()
11.66   File "/root/.cache/pypoetry/virtualenvs/myproject-VA82Wl8V-py3.11/lib/python3.11/site-packages/mountaineer/client_builder/builder.py", line 68, in build
11.66     asyncio.run(self.async_build())
11.66   File "/usr/lib/python3.11/asyncio/runners.py", line 190, in run
11.66     return runner.run(main)
11.66            ^^^^^^^^^^^^^^^^
11.66   File "/usr/lib/python3.11/asyncio/runners.py", line 118, in run
11.66     return self._loop.run_until_complete(task)
11.66            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
11.66   File "/usr/lib/python3.11/asyncio/base_events.py", line 653, in run_until_complete
11.66     return future.result()
11.66            ^^^^^^^^^^^^^^^
11.66   File "/root/.cache/pypoetry/virtualenvs/myproject-VA82Wl8V-py3.11/lib/python3.11/site-packages/mountaineer/client_builder/builder.py", line 94, in async_build
11.66     await self.build_javascript_chunks()
11.66   File "/root/.cache/pypoetry/virtualenvs/myproject-VA82Wl8V-py3.11/lib/python3.11/site-packages/mountaineer/client_builder/builder.py", line 477, in build_javascript_chunks
11.66     self.move_build_artifacts_into_project()
11.66   File "/root/.cache/pypoetry/virtualenvs/myproject-VA82Wl8V-py3.11/lib/python3.11/site-packages/mountaineer/client_builder/builder.py", line 495, in move_build_artifacts_into_project
11.66     self.view_root.get_managed_static_dir(tmp_build=True).rename(tmp_static_dir)
11.66   File "/usr/lib/python3.11/pathlib.py", line 1176, in rename
11.66     os.rename(self, target)
11.66 OSError: [Errno 18] Invalid cross-device link: '/usr/src/app/myproject/views/_static/tmp' -> '/tmp/tmpad4vf3eo/static'