Document missing-object primary-key metadata fix

Signed-off-by: Vu Anh Phung <vu.phung@databricks.com>

Author: vuanhphung

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - **Breaking:** require Node.js versions containing the CVE-2026-111497 Brotli decoder fix: 22.23.4+, 24.22.1+, or 26.12.1+. Node.js 20, 23, and 25 are no longer supported because those end-of-life lines have no fix.
+- Return empty results with the standard schema from Thrift `getPrimaryKeys()` when a catalog, schema, or table is missing, instead of throwing. (#553)
 
 ## 2.4.0