Fix intermittent ruff I001 error for _version import (#1460)

Add # isort: skip comment to the _version import in
cuda_pathfinder/cuda/pathfinder/__init__.py to prevent ruff from
inconsistently reordering the import based on whether _version.py exists.

Problem:
Ruff's import sorting (I001) behavior is inconsistent when imports
cannot be resolved. The _version.py file is generated by setuptools-scm
during the build process, so its existence depends on build state:

- When _version.py EXISTS (after a build):
  Ruff can resolve the import and wants to sort it alphabetically.
  Since _version comes after _headers alphabetically, ruff expects
  the import order: _dynamic_libs, _headers, _version.

- When _version.py DOESN'T EXIST (after git clean -fdx or fresh clone):
  Ruff cannot resolve the import and may skip checking it entirely,
  especially if cached as "unresolvable". This leads to inconsistent
  behavior where the same code passes or fails depending on build state.

Root Cause:
Ruff caches import resolution results. If the cache has stale data
where _version.py didn't exist, ruff may skip checking that import.
When the cache is refreshed or _version.py exists, ruff resolves it
and wants to sort it, triggering I001 errors inconsistently.

Solution:
Add # isort: skip comment to explicitly tell ruff to skip sorting
this import, regardless of file existence or cache state. This ensures
consistent behavior in all scenarios:
- After builds (when _version.py exists)
- After git clean (when _version.py doesn't exist)
- With fresh clones
- With stale ruff cache

The import is placed after the other imports (where it logically
belongs alphabetically) with the skip directive to prevent ruff from
moving it.

Author: rwgk

cuda_pathfinder/cuda/pathfinder/__init__.py

@@ -3,8 +3,6 @@
 
 """cuda.pathfinder public APIs"""
 
-from cuda.pathfinder._version import __version__  # noqa: F401
-
 from cuda.pathfinder._dynamic_libs.load_dl_common import DynamicLibNotFoundError as DynamicLibNotFoundError
 from cuda.pathfinder._dynamic_libs.load_dl_common import LoadedDL as LoadedDL
 from cuda.pathfinder._dynamic_libs.load_nvidia_dynamic_lib import load_nvidia_dynamic_lib as load_nvidia_dynamic_lib
@@ -14,6 +12,8 @@
 from cuda.pathfinder._headers.find_nvidia_headers import find_nvidia_header_directory as find_nvidia_header_directory
 from cuda.pathfinder._headers.supported_nvidia_headers import SUPPORTED_HEADERS_CTK as _SUPPORTED_HEADERS_CTK
 
+from cuda.pathfinder._version import __version__  # isort: skip  # noqa: F401
+
 # Indirections to help Sphinx find the docstrings.
 #: Mapping from short CUDA Toolkit (CTK) library names to their canonical
 #: header basenames (used to validate a discovered include directory).