Added theme version in design settings (#18623)

### Why this PR?

This PR adds back the current theme version in Design Settings screen


![image](https://github.com/TryGhost/Ghost/assets/8493007/88f475f6-9bba-4dda-8db7-0bddd2fee8a3)


- [x] There's a clear use-case for this code change, explained above
- [x] Commit message has a short title & references relevant issues
- [x] The build will pass (run `yarn test:all` and `yarn lint`)

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### <samp>🤖 Generated by Copilot at 2796daf</samp>

This pull request improves the code quality and user interface of the
design modal component for site settings. It applies code formatting
rules and shows the active theme version on the save button.

apps/admin-x-settings/src/components/settings/site/DesignModal.tsx

@@ -70,7 +70,7 @@ const Sidebar: React.FC<{
                     }}>
                         <div className='text-left'>
                             <div className='font-semibold'>Change theme</div>
-                            <div className='font-sm text-grey-700'>Current theme: {activeTheme?.name}</div>
+                            <div className='font-sm text-grey-700'>Current theme: {activeTheme?.name} - v{activeTheme?.package.version}</div>
                         </div>
                         <Icon className='mr-2 transition-all group-hover:translate-x-2 dark:text-white' name='chevron-right' size='sm' />
                     </button>