Remove nvim.desktop in favor of symlink

Moving to symlink fixes the following issues:
- App removes from launchers if you uninstall Nvim
- Nvim launches in the correct terminal without invalid desktop entry

Symlink setup moved to omarchy-nvim-setup (Ref:
https://github.com/omacom-io/omarchy-pkgs/commit/bb7a0f4c1f78d428bbe53bc3af2c91a9c8a5de3b)

migrations/1759782459.sh

@@ -1,3 +0,0 @@
-echo "Fix opening in nvim from files manager"
-
-cp -f $OMARCHY_PATH/applications/nvim.desktop ~/.local/share/applications/nvim.desktop

migrations/1761583837.sh

@@ -1,3 +1,7 @@
 echo "Ensure nvim started from app launcher always starts nvim not $EDITOR"
 
-cp $OMARCHY_PATH/applications/nvim.desktop ~/.local/share/applications/
+if [ -f /usr/share/applications/nvim.desktop ]; then
+  rm ~/.local/share/applications/nvim.desktop
+  ln -s /usr/share/applications/nvim.desktop ~/.local/share/applications/nvim.desktop
+  update-desktop-database ~/.local/share/applications
+fi