fix(files): restore getFileExtension import dropped during refactor

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/file-viewer.tsx

@@ -6,6 +6,7 @@ import { toError } from '@sim/utils/errors'
 import dynamic from 'next/dynamic'
 import { Skeleton } from '@/components/emcn'
 import type { WorkspaceFileRecord } from '@/lib/uploads/contexts/workspace'
+import { getFileExtension } from '@/lib/uploads/utils/file-utils'
 import { useWorkspaceFileBinary } from '@/hooks/queries/workspace-files'
 import { resolveFileCategory } from './file-category'
 import type { StreamingMode } from './text-editor-state'