fix cpath related errors

[madmaxieee]

Current way of configuring cpath use the full path of the downloaded binary without any '?', this causes any require statement that can't resolve before this cpath component to always resolve to the downloaded libfff_nvim, thus causing some unexpected bug in some other plugins or user code.

fixes errors like this:

Error executing vim.schedule lua callback: error loading module 'blink_cmp_fuzzy' from file '/Users/quolpr/.local/share/nvim/lazy/fff.nvim/lua/../target/libfff_nvim.dylib':
        dlsym(0x92987180, luaopen_blink_cmp_fuzzy): symbol not found
stack traceback:
        [C]: at 0x0103251790
        [C]: at 0x0103251b88
        [C]: in function 'require'
        ...l/share/nvim/lazy/blink.cmp/lua/blink/cmp/fuzzy/init.lua:17: in function 'set_implementation'
        .../.local/share/nvim/lazy/blink.cmp/lua/blink/cmp/init.lua:24: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>

[SandyJackson]

This addresses issue #164 and is a different, but similar approach to PR #165

Just to keep everything linked 👍

[madmaxieee]

ah, right, I didn't see that PR, thanks

[dmtrKovalenko]

I'll keep the other PR, thank you both for contributing. And sorry for the delay

[dmtrKovalenko]

No I actually will keep this one because I can not update that PR cause github sucks