fix: add no require git to rg command backend

Summary:

When using this backend in a directory that is not a git repository, it will
search though all the file. This is mostly a problem when using an alternative
source control like sapling.

When using this backend neovim will just hang until the rg command is done.
When searching node_modules you can imagine how long that takes. This does not
actually fix the issue however, it does make it search though less files.

Test Plan:

This has been used manually on a sapling repo. I have also added
`--no-require-git` to most of the rg defaults in other applications.

lua/ivy/backends/rg.lua

@@ -5,7 +5,7 @@ local rg = {
   command = "IvyRg",
   description = "Run ripgrep to search for content in files",
   keymap = "<leader>/",
-  items = utils.command_finder "rg --vimgrep --",
+  items = utils.command_finder "rg --no-require-git --max-columns 200 --vimgrep --",
   callback = utils.vimgrep_action(),
 }