test(python): expand minimal dependency coverage

Expand the Linux Python test run without pandas and pylance from two files to
the suite while retaining the regular dependency run for optional-package
modules.

Move optional imports into tests that need them and use Arrow assertions where
pandas is not required, preserving the existing behavioral assertions.

Validation:
- Physical no-pandas/no-pylance broad run: 2884 passed, 316 skipped, 8 existing
  marker cases deselected.
- Regular affected suite: 1687 passed, 39 skipped.
- Current-head hosted integration: all 15 checks and 4 workflows passed.

Co-authored-by: importcpp <57519936+importcpp@users.noreply.github.com>

.github/workflows/python.yml

@@ -161,7 +161,16 @@ jobs:
       - name: Test without pylance or pandas
         run: |
           pip uninstall -y pylance pandas
-          pytest -vv python/tests/test_table.py python/tests/test_namespace_no_pylance.py
+          # These modules still import optional packages during collection or
+          # exercise them throughout many tests; the full run above covers them.
+          pytest -m "not slow and not s3_test" -vv --durations=30 python/tests \
+            --ignore=python/tests/docs \
+            --ignore=python/tests/test_context.py \
+            --ignore=python/tests/test_db.py \
+            --ignore=python/tests/test_embeddings.py \
+            --ignore=python/tests/test_embeddings_slow.py \
+            --ignore=python/tests/test_namespace_integration.py \
+            --ignore=python/tests/test_query.py
       # Make sure wheels are not included in the Rust cache
       - name: Delete wheels
         run: rm -rf target/wheels