User is asked to unlock its keyring even if not needed

I'm using this project via copilot.lua - there is an open issue related to this problem https://github.com/zbirenbaum/copilot.lua/issues/725

Using the same APIs, after updating from version 1.503.0 to 1.506.0, (some) users are being asked to unlock their keyring while it's not needed.

Start by comparing the keyring-related behavior between versions 1.503.0 and 1.506.0, using the APIs referenced in the issue and the linked copilot.lua issue. The fix should prevent an unnecessary keyring unlock prompt while preserving it when the keyring is actually needed.

索引モデルが issue の本文から書いたものです。