omarchy-nvim: point monokai-pro at loctvl842 (repo not found)

The all-themes.lua spec references "gthelding/monokai-pro.nvim", a fork
that no longer exists on GitHub (HTTP 404). On every launch lazy.nvim
fails to clone it and reports "repository not found", and leaves a stale
lazy/monokai-pro.nvim.cloning marker so the error repeats.

Restore the canonical, actively maintained upstream
"loctvl842/monokai-pro.nvim" -- the value this line held before
80a278206 ("Match nvim themes"). It registers the same "monokai-pro"
colorscheme and still supports filter = "ristretto" plus the setup
override used by Omarchy 3.8's themes/ristretto/neovim.lua, so nothing
downstream changes except that the plugin resolves again.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011FcsS1gPeUiLSqqi4iKgzm

pkgbuilds/omarchy-nvim/lua/plugins/all-themes.lua

@@ -77,7 +77,7 @@ return {
 		priority = 1000,
 	},
 	{
-		"gthelding/monokai-pro.nvim",
+		"loctvl842/monokai-pro.nvim",
 		lazy = true,
 		priority = 1000,
 	},