langchain

2a3c5f83 - Update WhatsAppChatLoader regex to handle multiple date-time formats (#4186)

Update WhatsAppChatLoader regex to handle multiple date-time formats (#4186) This PR updates the `message_line_regex` used by `WhatsAppChatLoader` to support different date-time formats used in WhatsApp chat exports; resolves #4153. The new regex handles the following input formats: ```terminal [05.05.23, 15:48:11] James: Hi here [11/8/21, 9:41:32 AM] User name: Message 123 1/23/23, 3:19 AM - User 2: Bye! 1/23/23, 3:22_AM - User 1: And let me know if anything changes ``` Tests have been added to verify that the loader works correctly with all formats.