[lib] Increase join thread timeout

Summary:
Make it consistent with other request that can take longer.

https://linear.app/comm/issue/ENG-8958/invite-invalid-when-trying-to-join-the-comm-community

Test Plan: Check if joining a community through an invite link works on web.

Reviewers: kamil, inka

Reviewed By: inka

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D12999