refactor: remove unused oklchToRgb import from SongThumbnailInput component

- Eliminated the import of the oklchToRgb utility function from SongThumbnailInput.tsx to streamline the code following its removal from utils.ts. This change enhances code clarity and maintains consistency with recent refactoring efforts.

Author: tomast1337

apps/frontend/src/modules/song/components/client/SongThumbnailInput.tsx

@@ -2,7 +2,7 @@ import { useMemo } from 'react';
 import { UseFormReturn } from 'react-hook-form';
 
 import { BG_COLORS, THUMBNAIL_CONSTANTS } from '@nbw/config';
-import { cn, oklchToRgb } from '@web/lib/utils';
+import { cn } from '@web/lib/utils';
 import {
   Tooltip,
   TooltipContent,