Add SNOWFLAKE_AUTHENTICATOR env var for Snowflake CLI

The manage-test-db.sh script uses `snow sql --temporary-connection`
which reads SNOWFLAKE_AUTHENTICATOR from the environment. Without it,
the CLI defaults to password auth and fails with private key.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: eakmanrq <6326532+eakmanrq@users.noreply.github.com>

Author: eakmanrq

.github/workflows/pr.yaml

@@ -311,6 +311,7 @@ jobs:
       SNOWFLAKE_ACCOUNT: ${{ secrets.SNOWFLAKE_ACCOUNT }}
       SNOWFLAKE_USER: ${{ secrets.SNOWFLAKE_USER }}
       SNOWFLAKE_WAREHOUSE: ${{ secrets.SNOWFLAKE_WAREHOUSE }}
+      SNOWFLAKE_AUTHENTICATOR: SNOWFLAKE_JWT
       DATABRICKS_SERVER_HOSTNAME: ${{ secrets.DATABRICKS_SERVER_HOSTNAME }}
       DATABRICKS_HTTP_PATH: ${{ secrets.DATABRICKS_HTTP_PATH }}
       DATABRICKS_ACCESS_TOKEN: ${{ secrets.DATABRICKS_ACCESS_TOKEN }}