Migrate to new async/coroutine module

[linrongbin16]

As discussed in #257 , there's a issue in previous version of "gitlinker.commons.async". I just updated it in linrongbin16/commons.nvim#311.

The new "async" module is a much simpler and easier coroutine module with only two APIs: wrap and void, but works correctly on Fedora 41 workstation edition (tested in #264).

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Since this migration has no visible benefits for users (#258 already fixed the bug), I will pend it until there's a proper timing to do it.