Chore(beta): drop lancedb dependency

Fixes #12970: the package whose wheels SIGILL on non-AVX2 CPUs is no
longer installed at all.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -49,7 +49,6 @@ dependencies = [
   "ijson>=3.2",
   "imap-tools~=1.13.0",
   "jinja2~=3.1.5",
-  "lancedb~=0.33.0",
   "langdetect~=1.0.9",
   "llama-index-core>=0.14.21",
   "llama-index-embeddings-huggingface>=0.6.1",
@@ -62,7 +61,6 @@ dependencies = [
   "openai>=2.32",
   "pathvalidate~=3.3.1",
   "pdf2image~=1.17.0",
-  "pyarrow>=16",
   "python-dateutil~=2.9.0",
   "python-dotenv~=1.2.1",
   "python-gnupg~=0.5.4",