v3.19.1

Commits:

• d04b303 Update stale
• e933143 Fix typo in readme (#1385)
• 6011b67 Update readme
• 033088d Optimize object strip case (#1393)
• d40a5eb Fix refine with type guard signature (#1404)
• 2893e16 Make unknown input type for preprocess
• 3b75ae5 3.19.1