revert: cmp.visible() seems to be very slow

This reverts commit 5e2682d.

Author: dcampos

lua/snippy/main.lua

@@ -336,7 +336,7 @@ function M.cut_text(mode, visual)
 end
 
 function M._mirror_stops()
-    if not util.pumvisible() and buf.current_stop ~= 0 then
+    if buf.current_stop ~= 0 then
         buf.mirror_stop(buf.current_stop)
     end
 end

lua/snippy/util.lua

@@ -57,12 +57,4 @@ function M.merge_snippets(current, added)
     return result
 end
 
-function M.pumvisible()
-    local ok, cmp = pcall(require, 'cmp')
-    if ok then
-        return cmp.visible()
-    end
-    return vim.fn.pumvisible() == 1
-end
-
 return M