ci: fix more flakey tests by adding condis

Author: ibhagwan

tests/win_spec.lua

@@ -316,6 +316,7 @@ T["win"]["reuse"] = new_set({
       },
       previewer = function() return require("fzf-lua.test.previewer").builtin end,
       __after_open = function()
+        child.wait_until(function() return child.lua_get([[_G._fzf_load_called]]) == true end)
         if helpers.IS_WIN() then vim.uv.sleep(250) end
       end,
     }