Kernels unittest fix ljl (#61)

* feat(tests): replace manual sp_group retrieval with module attribute

Replace calls to `_get_sp_group_from_device_mesh` with direct access to `sequence_parallel._sp_group` in sequence parallel attention tests. This simplifies the test setup by using the already initialized group stored in the module, improving code clarity and reducing redundancy.

* feat(tests): improve kernel availability check in test_function_kernel

Add additional imports and a try-except block to verify that the 'kernels-test/flattened-build' kernel can be successfully loaded in the current environment before proceeding with the test. This prevents test failures due to environment-specific loading issues and provides a more informative skip message.

Author: meichangsu1

tests/kernel/test_function_kernel.py

@@ -54,10 +54,21 @@ def test_flattened_build_replaces_function(self):
             self.skipTest(f'HuggingFace unreachable: {e}')
         try:
             from kernels import has_kernel
+            from kernels._versions import select_revision_or_version
+            from kernels.utils import get_kernel
         except Exception:
             self.skipTest('kernels package missing has_kernel.')
         if not has_kernel('kernels-test/flattened-build'):
             self.skipTest('kernels-test/flattened-build not available.')
+        try:
+            revision = select_revision_or_version(
+                'kernels-test/flattened-build',
+                revision=None,
+                version=None,
+            )
+            get_kernel('kernels-test/flattened-build', revision=revision)
+        except Exception as exc:
+            self.skipTest(f'kernels-test/flattened-build cannot be loaded in this env: {exc}')
 
         _ensure_test_packages()
         module_name = 'tests.kernel._tmp_flattened_build_module'