switch completion list abort keymap to Ctrl+C

so as to not overload Esc, which has been a little frustrating to me.

sometimes i find myself with a completion list open, and realizing i
want to switch to normal mode to do something. so i hit Esc only once
thinking that will switch me to normal mode ... but because a
completion list was open, that single Esc key press only aborted/closed
the completion list and left me in insert mode ... which i then don't
realize and end up accidentally typing a bunch of gibberish in to the
buffer instead.

lua/plugins/nvim-cmp.lua

@@ -80,7 +80,7 @@ return {
           ['<C-y>'] = cmp.mapping.confirm { select = true },
 
           -- Cancel/abort any selected/partial completion and close the completion list.
-          ['<Esc>'] = cmp.mapping.abort(),
+          ['<C-c>'] = cmp.mapping.abort(),
 
           -- If you prefer more traditional completion keymaps,
           -- you can uncomment the following lines