treewide: convert package options to use mkPackageOption (#7116)

This commit converts `package = mkOption` declarations throughout the
codebase to use the more modern and consistent `lib.mkPackageOption`
function.

Key changes:
- Simple package options: `mkOption { type = types.package; default = pkgs.foo; }`
  becomes `lib.mkPackageOption pkgs "foo" { }`
- Package set options: Uses correct package set as first argument with
  `pkgsText` parameter (e.g., `lib.mkPackageOption pkgs.vimPlugins "plugin" { pkgsText = "pkgs.vimPlugins"; }`)
- Removes redundant descriptions that just restate the package name
- Preserves examples and extra context where meaningful
- Handles submodule plugin options properly with `null` defaults

This modernizes the option declarations and makes them more consistent
with current nixpkgs patterns while maintaining full backward compatibility.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

modules/programs/tmux.nix

@@ -19,9 +19,11 @@ let
 
   pluginModule = types.submodule {
     options = {
-      plugin = mkOption {
-        type = types.package;
-        description = "Path of the configuration file to include.";
+      plugin = lib.mkPackageOption pkgs.tmuxPlugins "plugin" {
+        example = "pkgs.tmuxPlugins.sensible";
+        default = null;
+        pkgsText = "pkgs.tmuxPlugins";
+        extraDescription = "Path of the configuration file to include.";
       };
 
       extraConfig = mkOption {