fix: add missing import

Author: atinux

src/runtime/server/utils/blob.ts

@@ -4,6 +4,7 @@ import type { R2Bucket } from '@cloudflare/workers-types/experimental'
 import { ofetch } from 'ofetch'
 import mime from 'mime'
 import type { H3Event } from 'h3'
+import { setHeader } from 'h3'
 import { defu } from 'defu'
 import { randomUUID } from 'uncrypto'
 import { parse } from 'pathe'