Guard pyarrow import behind importorskip in lancedb tests

The lancedb adapter and CLI audit tests did `import pyarrow as pa` at
module top, before `pytest.importorskip("lancedb")`. On CI (where the
detectors+dev extras intentionally omit backend deps) pyarrow is
absent too, so collection errored before the importorskip could fire.
Move the pyarrow import below the lancedb importorskip and use
importorskip for it as well so the tests skip cleanly, matching the
chroma/pinecone tests' pattern.

Author: jaschadub

tests/test_adapter_lancedb.py

@@ -10,10 +10,10 @@
 from __future__ import annotations
 
 import numpy as np
-import pyarrow as pa
 import pytest
 
 lancedb = pytest.importorskip("lancedb")
+pa = pytest.importorskip("pyarrow")
 
 from vectorpin import Signer, Verifier
 from vectorpin.adapters import PIN_METADATA_KEY, LanceDBAdapter

tests/test_adapter_lancedb_symbiont.py

@@ -35,10 +35,10 @@
 import time
 
 import numpy as np
-import pyarrow as pa
 import pytest
 
 lancedb = pytest.importorskip("lancedb")
+pa = pytest.importorskip("pyarrow")
 
 from vectorpin import Signer, Verifier
 from vectorpin.adapters import PIN_METADATA_KEY, LanceDBAdapter

tests/test_cli_audit.py

@@ -16,11 +16,11 @@
 from pathlib import Path
 
 import numpy as np
-import pyarrow as pa
 import pytest
 
 lancedb = pytest.importorskip("lancedb")
 chromadb = pytest.importorskip("chromadb")
+pa = pytest.importorskip("pyarrow")
 
 from vectorpin import Signer
 from vectorpin.adapters import (